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Tuff Stuff Riddles

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Some of these are difficult, so challenge yourself!

A traveller comes to a fork in the road which leads to two villages. In one village the people always tell lies, and in the other village the people always tell the truth. The traveller needs to conduct business in the village where everyone tells the truth. A man from one of the villages is standing in the middle of the fork, but there is no indication of which village he is from. The traveller approaches the man and asks him one question. From the villager's answer, he knows which road to follow. What did the traveller ask?
 

Reveal Answer

The traveler asked "which road goes to your village". He would then take the road the villager pointed to because a truthful person would point toward the truthful village, and the liar would also point to the truthful village since he is a liar and, therefore, could not point to his own village.

A man walks into an art gallery and concentrates on one picture in particular. The museum curator notices this and asks the man why he is so interested in that one painting. The man replies, "Brothers and sisters have I none, but that man's father is my father's son."

Who is in the painting?
 

Reveal Answer

The son of the man who was studying the painting.

Dee Septor, the famous magician, claimed to be able to throw a ping-pong ball so that it would go a short distance, come to a complete stop, and then reverse itself. He also added that he would not bounce the ball off any object, or tie anything to it. How could he perform this trick?
 

Reveal Answer

He threw the ball straight up in the air!

Name four days of the week that start with the letter "t"?
 

Reveal Answer

Tuesday, Thursday, today, and tomorrow!

A man has to get a fox, a chicken, and a sack of corn across a river. He has a rowboat, and it can only carry him and one other thing. If the fox and the chicken are left together, the fox will eat the chicken. If the chicken and the corn are left together, the chicken will eat the corn. How does the man do it?
 

Reveal Answer

 

  1. man carries chicken to other side
  2. man returns alone and takes fox to other side
  3. man leaves fox but returns with chicken;
  4. man leaves chicken and carries corn to other side;
  5. man leaves corn with the fox and returns alone;
  6. man gets chicken and takes it to other side.

A train leaves from New York City (NYC) heading towards Los Angeles (LA) at 100 mph. Three hours later, a train leaves LA heading towards NYC at 200 MPH. Assume there's exactly 2000 miles between LA and NYC. When they meet, which train is closer to New York City?
 

Reveal Answer

When they meet, they're both at the same spot, therefore they are both the same distance from New York City!

There are 3 black hats and 2 white hats in a box. Three men (we will call them Tom, Bob, and Bill) each reach into the box and place one of the hats on his own head. They cannot see what color hat they have chosen. The men are situated in a way that Tom can see the hats on Bob and Bill's heads, Bob can only see the hat on Bill's head and Bill cannot see any hats. When Tom is asked if he knows the color of the hat he is wearing, he says no. When Bob is asked if he knows the color of the hat he is wearing he says no. When Bill is asked if he knows the color of the hat he is wearing he says yes and he is correct. What color hat and how can this be? There is no play on words and there are no tricks.
 

Reveal Answer

Tom must not see two white hats on Bob or Bill, or he would know his own hat must be black (since there are only two white hats). So Tom's answer establishes that at least one of the hats on Bob and Bill is black. Therefore, Bob knows that he and Bill are either both wearing black, or one is wearing black and one is wearing a white hat. If he sees that Bill is wearing a white hat, then he would know his own hat had to be black. But Bob instead says he doesn't know what color hat he is wearing, which means Bill's hat is not white and must be black. Therefore, Bill knows he is wearing a black hat.

boy looking up toward hair

Suppose there is only one barber shop in your town, and it employs two barbers. One of the barbers has a nice, neatly trimmed head of hair. The other's hair is a complete mess. Which of the two barbers should you go to and why?
 

Reveal Answer

Since there are only two barbers in town, it's safe to assume they cut each others hair. This being the case, you should sit down with the barber with the messy hair.


In a major league baseball game, a pitcher faced only 27 batters. Every batter he faced, he struck out. He allowed no hits and no runs, yet his team lost 4-0. How could this be?

Reveal Answer

The pitcher came in as a relief pitcher.

A farmer in California owns a beautiful pear tree. He supplies fruit to a nearby grocery store. The store owner has called the farmer to see how much fruit is available for him to purchase. The farmer know that the main trunk has 24 branches. Each branch has 12 boughs and each bough has 6 twigs. Since each twig bears one piece of fruit, how many plums will the farmer be able to sell?

Reveal Answer

None -- from that tree anyway. A pear tree cannot produce plums.

No sooner spoken than broken. What is it?

Reveal Answer

Silence.

A magician is standing on a concrete floor holding a raw egg with his hand outstretched. Without the aid of any objects, he is able to drop the egg two feet without breaking it's shell. How does he do it?
 

Reveal Answer

He simply holds the egg higher than two feet, and then releases the egg. The first two feet it will fall without breaking.

There are two books sitting side by side, consisting of exactly 100 pages. The book on the left is upside down. If you add the page number at the extreme left side of the book on the left to the page number at the extreme right side the right hand book, what is the total?
 

Reveal Answer

The total is two.

You're in a cement room with no windows or doors. The only thing you have is a mirror and a piece of wood. How do you get out?
 

Reveal Answer

You look in the mirror to see what you "saw", take the "saw" and cut the piece of wood in half. Put the two halves together to make a "whole", and then just crawl out through the "whole"! (Of course, kids, don't forget that the type of "hole" you could crawl through is spelled differently than a "whole" as used in a "whole" piece of something!)

A boy was locked in a room by some robbers. All that is in the room is a piano, calendar, and a bed. The room is locked from the outside. What does he eat, drink, and how does he get out?

Reveal Answer

He eats the "dates" on the calendar, gets water from the waterbed, and uses the piano key to escape.

"The two plastic jugs" Riddle: There are two plastic jugs filled with water. How could you put all of this water into a barrel, without using the jugs or any dividers, and still tell which water came from which jug?
 

Reveal Answer

Freeze one or both of the jugs, then cut the plastic away leaving only the ice. You could now put them into the barrel and still tell which water came from which jug.

What do these three have in common: Dogs, Diamonds, and Double Plays
 

Reveal Answer

They are best friends of something: Man's best friend, a girl's best friend, and a pitcher's best friend.

Can you think of words with all five vowels in them? And what word has all five vowels in alphabetic order?
 

Reveal Answer

"Sequoia" "facetious" (vowels are in order) or "facetiously" (in order, and includes Y); abstemious and abstemiously (again with the Y!)

What word has 5 letters but is pronounced like only one letter?
 

Reveal Answer

"Queue", pronounced as the letter 'Q'.

There is a frog stuck in a 60 foot well. How many days will it take the frog to get out if for every day he jumps five feet up, but then falls back three feet?
 

Reveal Answer

29 days. The last jump he was out of the well so he did not fall three feet back!

What would you be sure to find in the middle of Toronto?
 

Reveal Answer

An "o" (TorOnto)

A baseball team had won a game 19-17. No errors. But not a single man crossed the plate. How could this be?
 

Reveal Answer

It was a woman's team; or the men were all married (not single men!)

Uncle Sam opens door number 1

On the game show Let's Make A Deal, Monty Hall shows you three doors. Behind one of the doors is a new car,the other two hide goats. You choose one door, perhaps #1. Now Monty shows you what's behind door #2 and it's a goat. He gives you the chance to stay with your original pick or select door #3. What do you do?
 

Reveal Answer

You should always abandon your original choice in favor of the remaining door (#3). When you make your first choice the chance of winning is 1 in 3 or 33%. When you switch doors, you turn a 2 in 3 chance of losing in the first round into a 2 in 3 chance of winning in the second round.

There were two fathers and two sons on a boat fishing. They each caught a fish, but only three fish where caught. How can this be so?
 

Reveal Answer

There was a Grandfather, his son, and his son's son in the boat. Two fathers and two sons.

An Arab sheikh tells his two sons to race their camels to a distant city to see who will inherit his fortune. The one whose camel is slower will win. Reluctantly, the brothers started out on this unconventional "race". After wandering aimlessly for days, they came across a wise man and asked him for advice. After hearing the advice of the wise man, the brothers jump on the camels and race as fast as they can to the city. What advice did the wise man offer?
 

Reveal Answer

He suggested they switch camels since it was obvious they were afraid that their camel was faster than the other's.

volcano ready to erupt

A volcano erupts in the dark of the night. Four people, carrying only one flashlight, run for their lives. They come to a canyon. There's a footbridge that spans the canyon. The bridge can only support 2 people at a time. Since it's dark, they must use a flashlight to cross. Therefore, after 2 people cross safely, one has to go back to bring the flashlight back to the other side.

The people, suffering from different injuries, travel across the bridge at different speeds. Person #1 takes 1 minute, person #2 takes 2 minutes, person #3 takes 5 minutes, and person #4 takes 10 minutes. Two people crossing the bridge will travel at the speed of the slower person. There are only 17 minutes before the lava destroys the bridge. Find a logical solution where all four people reach the other side safely in 17 minutes or less—but this solution cannot include having any of them go only halfway across, or go across in the dark, or throw the flashlight across, etc. AND REMEMBER: You also have to count the time it takes to go back across the bridge with the flashlight!
 

Reveal Answer

Solution 1:

  1. Persons 1 and 2 cross the bridge (elapsed time 2 minutes)
  2. Person 1 returns (elapsed time 3 minutes)
  3. Persons 3 and 4 cross the bridge (elapsed time 13 minutes)
  4. Person 2 returns (elapsed time 15 minutes)
  5. Persons 1 and 2 cross the bridge (elapsed time 17 minutes).
Solution 2 has Person 2 returning in (2) and Person 1 returning in (4).
lightbulb

In the dark!
In the basement there are 3 light switches in the "off position." Each switch controls one of three light bulbs on the floor above. You may turn on any of the switches, but you may only go up stairs one time to see which light(s) were affected. How can you determine which switch controls each particular light bulb?
 

Reveal Answer

Turn any one switch to the "on" position for 5 minutes. Then turn that switch "off" and quickly turn on one of the other two switches to the "on" position. Then run upstairs and touch the two lights that are "off." One of them will be "hot" because is was turned on for 5 minutes. >Obviously the "hot" bulb is controlled by the first switch you turned "on." The light that is currently "on" is controlled by the switch you last turned "on." The "cold" bulb that is "off" >is controlled by the only switch left. When solving problems we often need to use all our senses.

pills

There are eight pills. They are all the same size and color. One pill weighs slightly more than the others and it is poisonous. You have a balanced scale and can only use it twice. How can you find the poisoned pill?
 

Reveal Answer

Take any six pills and divide them into two groups of three each; if the two groups weigh out evenly, weigh the remaining two pills to find the poisoned one. If the two groups of three do not weigh out evenly, simply take two out of the three pills from the heavier scale and weigh them (using the scale a second time). The two pills will either weigh the same, in which case the remaining pill is the poisoned one -- or one of the two pills on the scale will weigh more -- Voila!

If today is Monday, what is the day after the day before the day before tomorrow?
 

Reveal Answer

Monday...today!

Ahoy, blow, chin, defy, erst, flux, gist, hint, imps, know, lops, most. Twelve reasonably common words. Apart from all having four letters, what do they have in common? Can you provide a five-letter word having the same property? And a six-letter one?
 

Reveal Answer

The words all have their letters occurring in alphabetical order. A similar five-letter word is BELOW, and ALMOST is a six-letter one.

If Susan is 10, Arabella is 20, and Jim and Neal are both 5, but Richard is 10, how much would Jennifer be using this system?
 

Reveal Answer

Jennifer would be a "fifteen", because the only system that could be noted from the samples given was one that awarded "five" for each syllable of their names.

The same five letters can be anagrammed (arranged in different order) into four different words to fill in the blanks in the sentence to make (somewhat) good sense. What are the missing words from the paragraph below -- remember, they all have the same letters.

A farmer with hundreds of _ _ _ _ _, deeply _ _ _ _ _ about the amount of rainfall, and _ _ _ _ _ around with watering the ground because it is dry enough to _ _ _ _ _ him about the possibility of crop failure.
 

Reveal Answer

ACRES, CARES, RACES, and SCARE (Letters: AECRS)

A bank customer had $100 in his account. He then made 6 withdrawals, totaling $100. He kept a record of these withdrawals, and the balance remaining in the account, as follows:

$ Value of
Withdrawals
$ Value of
Balance remaining
$50 $50
25 25
10 15
8 7
5 2
2 0
--- ---
$100 $99

When he added up the columns as above, he assumed that he still had $1 in the bank. Was he right?
 

Reveal Answer

There is no reason whatever why the customer's original deposit of $100 should equal the total of the balances left after each withdrawal. It is purely coincidental that the total of the right-hand column of remaining balances is close to $100.

A census taker approaches a house and asks the woman who answers the door,"How many children do you have and what are their ages?" The woman replied "I have three children. The product of their ages is 36, the sum of their ages is equal to the address of the house next door." The census taker walked next door, but then came back and said, "You didn't give me enough information." The woman replied, "I can't talk now -- I have to go. I hear my oldest child calling." The census taker then says -- "That's okay. I have everything I need now."

Question: What are the ages of each of the three children and why did the census taker decide he had all he needed after the second visit?
 

Reveal Answer

The reason the census taker could not initially figure out the children's ages even after determining that the number on the house next door was 13, is that there were still two possibilities for the kid's ages: 9 + 2 + 2 and 6 + 6 + 1...both of which equal 13 and have a produce of 36. But he didn't know if the twins were older, or the single child. But when the home owner stated that her "oldest" child was calling, the Census taker presumed that there was a single oldest child, rather than twins, since it was unlikely of her to refer to one of a set of twins as her oldest child. Therefore, the children's ages were presumed to be 9, 2, and 2.

A man has recently escaped from prison and is making his way home on foot. He is walking along a straight rural country lane in bright daylight. He has walked about two miles from the prison, when he sees a police car coming toward him. Despite knowing that all squads would be out looking for him, he ran towards the car for a short while, and and then turned and ran into the woods to hide. Why did he initially run towards the police car?
 

Reveal Answer

The man is on a bridge when he spots the police car coming toward him. He's nearly across the bridge so the quickest way out of danger is to run forward.

Here is a rather simple question with a "yes" or "no" answer. It just happens to be phrased in a roundabout way, but that shouldn't disturb you if you find a way to reduce it to it's fundamentals.

"If the puzzle you solved before you solved the puzzle you solved after you solved the puzzle you solved before you solved this one, was harder than the puzzle you solved after you solved the puzzle you solved before you solved this one, was the puzzle you solved before you solved this one harder than this one?" Yes or no?
 

Reveal Answer

 

  1. The one you did after the one you did before this one, IS this one. In other words:
  2. "....the puzzle you solved after you solved the puzzle you solved before you solved this one" IS this one.
  3. Hence the question may be rephrased this way: "If the puzzle you solved before this one was harder than THIS ONE, was the puzzle you solved before this one harder than THIS ONE?"
  4. The answer to this question is obviously YES.

So far as I can determine, only one other word can be made from the letters of INSATIABLE. Find it.
 

Reveal Answer

Banalities

Each of these words can be changed into something edible by scrambling the letters and making a new word. What foods can you produce from these words when rearranged?

PLAYERS
SANDIER
ASSUAGE
BARELY
 

Reveal Answer

Parsley, sardine, sausage and barlely

spider running around web

A woman walks into a restaurant and asks the man behind the counter for a glass of water. The man pulls out a big hairy spider and tosses it toward the lady. A few minutes later the woman thanks the man and walks out of the restaurant. Why?
 

Reveal Answer

The woman asked the man for a glass of water because she had the hiccups. So the man pulled out a harmless, but very big and ugly pet spider to scare her. The scare cured her hiccups, so she thanked the man and left.

I purchased two different pieces of candy. Together they cost $1.10. One candy cost one dollar more than the other candy. What was the price of each piece of candy?
 

Reveal Answer

One was $1.05 and the other was 5 cents.

Today as I was running late for work, I quickly got dressed and threw a t-shirt on in the dark. I had it on inside out with my right arm in the left sleeve, and my left arm in the right sleeve. Where was the label?
 

Reveal Answer

Outside back.

How many common four letter words can you make from the letters E A M N using all the letters in each word?
 

Reveal Answer

Four: mean, mane, amen, name

digging a hole

If it takes 6 men 6 days to dig 6 holes, how long will it take 3 men to dig half a hole?
 

Reveal Answer

There is no such thing as a half a hole. A hole is still a hole regardless of its size.

It has my name, yet it is not me! Who is speaking, and what is "IT"?
 

Clue

Think of an ancient person, either real or mythical.


Reveal Answer

The strong man "Atlas" and an Atlas (book of maps). But a lot of answers would work...for example, one of our readers suggested that it could be any of the mythological gods speaking of the planets that were named for them, such as Mars, Jupiter, Neptune, Venus, etc.)

What two words, when combined, hold the most letters?
 

Reveal Answer

Post office!

What starts with an "e," ends with an "e" and usually contains only one letter?
 

Reveal Answer

Envelope!

What is the beginning of eternity, the end of time and space; the beginning of every end and the end of every place?
 

Reveal Answer

The letter "E"!

"Pre-School" Test for you:
Which way is the bus below traveling...toward the left or the right?

outline of a bus with windows and wheels included

Can't make up your mind? Look carefully at the picture again. Pre-schoolers all over the United States were shown this picture and asked the same question, and 90% of them gave the correct answer!

 

Reveal Answer

The bus is traveling to the left. When asked why they decided the bus is traveling to the left, they answered: "Because you can't see the door to get on the bus."

You must cut a gold chain to pay someone for 7 days of service. The chain has 7 links on it, and you agree on a price of one link per day. The employee will not work without receiving that day's pay each afternoon, but you do not wish to give him more than his daily payment for the fear that he will not return. Therefore, you must cut some of the links on the chain to make the daily payments. What is the smallest number of links you need to cut so that the employee receives only one link each day?

 

Reveal Answer

The chain can be divided with just three cuts. When you cut a link, you can remove the adjacent link from each side. So first cutting the middle (fourth) link will yield a single link and two chains 3 links long. Then cutting each of those in the middle of the remaining two sections (of three links each) will divide the chain into individual links. HOWEVER, one of our visitors has suggested that IF the worker agrees to not spend his pay until after the week is over AND to do an exchange most days, you can pay him each day by making only ONE cut in the chain. First, cut the link three from the end. This will give you a single link (that has been cut), a chain of two links and a chain of four links. Now pay the man in the following way.
Day 1: give him a single link (Pay = 1 link)
Day 2: Exchange the single link with the double link (Pay = 2 links)
Day 3: Give him a single link (Pay = 3 links)
Day 4: Exchange the 3 links (single link and the 2 link chain)
for the chain of 4 links (Pay = 4 links)
Day 5: Give him the single link (Pay = 5 links)
Day 6: Exchange the single link for the double link (Pay = 6 links)
Day 7: Give him the single link (Pay = 7 links)

While driving home after a hard day's work, I came upon the following problem. An entire town had been painted black; the roads, pavements, buildings, hedges, and everything that did not move had been painted black. In addition, my vehicle's headlights were not working, no moon was visible, and power was off in the area, so there were no street or house lights around. At that moment, I entered a curve where a solid black dog (deaf, and thus unaware of the approaching car) was sitting in the road. He had his back to me, so there was not even a glint in his eye, yet I was able to swerve round him quite easily and without danger. How was this achieved?

 

Reveal Answer

It was 2 o'clock on a lovely sunny afternoon!

A man has an acreage where grass grows continuously and evenly. If 20 cows eat all the grass in 96 days and 30 cows eat all of the grass in 60 days, then how long does it take 70 cows to eat all of the grass?

 

Reveal Answer

Let's say one cow can eat X pounds of grass per day. The field grows Y pounds of grass per day. At the start the field already has N pounds of grass standing. At the end, the field has zero pounds of grass remaining. So we set up the equations for the amount of grass for the two cases, adding growing grass and subtracting eaten grass:
for 96 days:
N + 96Y - 20x96 X =0
For 30 cows eating for 60 days:
N + 60Y - 30x60 X = 0
Or N + 96Y - 1920X = 0 and
N + 60Y - 1800X = 0
Subtract the two equations and we get: 36Y - 120X = 0, or 36Y =120X or 3Y = 10X
In other words, in one day ten cows can eat as much as the field grows in three days.Now we substitute this back into either of the two starting equationsto find how much grass (N) was in the field at the start:
>N + 60Y - 1800X = N + 60Y -540Y = 0
And N = 480Y
Now we set up the equation for 70 cows eating and the field growing for T days, until the grass is gone:
N + TY - 70 TX = 0, or 480Y + TY - 21TY = 0 480Y -20TY = 0
thus T = 24.
So the 70 cows finish off the field in 24 days.

You have three houses or squares drawn on paper, and below them three smaller squares representing gas, water, and electric service. Can you draw a line to get each utility into each house (9 total lines) without crossing over any line, changing the size of some of the houses, or going through one house to reach another?

picture of three houses

 

Reveal Answer

No -- the statement 'drawn on paper' implies that this is a 2D surface, and in two dimensions the problem has no solution. The best result you may get using the drawing above is only eight proper connections. But in three dimensions, the problem can pretty easily be solved. There is a real lesson in geometry here -- whether the six objects with connections are houses or just geometric points, the true answer is that one cannot make the nine connections on a two-dimensional surface without one of the lines crossing. Adding size to the houses and/or running lines through the houses, etc., simply avoids the problem by just changing the rules, rather than finding the true solution. One of the lessons, particularly in mathematics, is to discover what is impossible and thus can be excluded in solutions of other problems. The answer is not always to hammer the problem into a different one that looks solvable.

Good at math? Try this one....
1=3
2=3
3=5
4=4
5=4
6=3
7=5
8=5
9=4
10=3

So what does
11=?
12=?
 

Reveal Answer

11=6 and 12=6 (the number of letters in the number's name)

What do these words have in common: age, blame, curb, dance, evidence, fence, gleam, harm, interest, jam, kiss, latch, motion, nest, order, part, quiz, rest, signal, trust, use, view, win, x-ray, yield, zone?

 

Reveal Answer

All the words can be used as both nouns and verbs.

What are the science teacher's favorite states?

 

Reveal Answer

Solid, liquid, and gas...the states of matter!

You have three containers. One has only red marbles, one has only blue marbles and the third has an equal number of red and blue marbles. The labels on the containers have intentionally been switched so that each container is now marked incorrectly.

Your job is to relabel the containers correctly. Of course you could just look in the containers to find out which labels match, but can you do it without looking into each container? Reach into any one of the containers and select one marble. Can you now correctly label all three containers? If not, select a second marble from any container. What is the fewest number of marbles you need to inspect in order to correctly label each container?
 

Reveal Answer

You would only need to take out one marble because we know that all of the labels are incorrect. So you pull one marble out of the container labeled "mixed." If red comes out, you know that has to be the all-red container, so you put the red label on it. The container labelled "Blue" must then be labelled "mixed" because you know it is also labeled incorrectly, and therefore can't be blue. You would label the last container blue because that is the only color/container combo left. Of course, if the first marble you pulled out from the container labeled "mixed" is blue marble, then you solve the problem in the same general way.

During a school lunch break, ten kids are discussing after school jobs. In particular, they would like to know their average monthly salary (for the ten of them), but no one wants to admit openly exactly what they make. Can you devise a way for them to calculate their average (mean) salary without anyone having to tell anyone else what their individual salaries are?
 

Reveal Answer

Although there may be other solutions, here is a simple one: The first person takes his monthly salary (lets say $100), adds an arbitrary amount that only he knows (lets say $475) and whispers that number ($575) to the second person. The second person then adds his monthly salary (lets say $150) to that value and whispers the new total ($725) to the third person. The third person adds in his salary, whispers the new total to the fourth person and so on until the tenth person adds in his salary and whispers the final total to the first person. The first person then subtracts his arbitrary number from that total, divides by 10, which produces (assuming that no one made an error in arithmetic!) the average monthly salary for the group without anyone having to divulge their salary to anyone else.

rowboat on a river

What is the fastest time that a group of four people can row to the other side of the river with the following rules in place?

 

Reveal Answer
  1. #2 rows #1 across in 2 minutes
  2. #1 returns in 1 minute
  3. #10 rows #5 across in 10 minutes
  4. #2 returns in 2 minutes
  5. #2 rows #1 across in 2 minutes

Total is 17 minutes, and steps 2) and 4) can be interchanged. The key is to have #10 row #5 across and have a faster rower waiting on the other side to take the boat back.

black hat facing wall from the left, white hat, followed by black, then white, facing the wall from the other side

Four men are standing in a line as shown above and they cannot turn their heads. There is a brick wall between A and B that they cannot see through. They know that they each have one hat, and that of the four hats two are black and two are white. They cannot see the color of the hat that they are wearing. In order to be released from the line, they must call out the color of their hat. If they are wrong, no one can leave. They are not allowed to talk to each other, and they have been given ten minutes to figure out their hat color. After 1 minute:

This is not a trick question and there are no outside influences nor any other ways of communicating. They cannot move or see behind them, nor can they see through the wall.
 

Reveal Answer

C would call out, because he would know that if his hat were the same color as B's hat, then D would have known that his own hat was the opposite color of B and C's hat and would have called out. Since D did not speak then C knows that his hat is the opposite color of B's.

In a recent random drawing of three digits, the number 361 was drawn; immediately afterward in a random drawing of four digits, 2401 was drawn. Both of these numbers have something unusual in common -- what is it? And what are the chances of this happening again, remembering that in a random drawing numbers can begin with one or more zeroes.
 

Reveal Answer

Both numbers are perfect squares (19 squared and 49 squared). The three number drawing has exactly 1000 possible outcomes (000-999) The four number drawing has exactly 10,000 possible outcomes (0000-9999). To see how many squares are possible, take the square root of the maximum number and "round up" (to count the 000, which is a perfect square). Thus, since the square root of 999 is 31.6, there are 32 possible squares in the three number drawing (the squares of 0 through 31). Similarly, for the four number drawing, there are 100 possible squares (the squares of 0 through 99). Thus, the likelihood of both numbers being a squared number is (32/1000) x (100/10000) or 0.00032 (a little over 3 chances in 10,000).

Two postmen meet on their routes and they start talking.
Postman A says: "I know you have 3 sons, how old are they?"
Postman B says: "If you take their ages in years, and multiply them together, the result is your age."
A: "That`s not enough info"
B: "The sum of the 3 numbers equals the number of windows in that
building over there."
A: "Hmm... that`s still not enough."
B: "My middle son is red-haired."
A: "Ah, now I see!"
How old are the 3 sons?
 

Reveal Answer

With a little bit of work, you can discover that only one solution is possible: the kids must be 1, 5, and 8 because a solution with the same A and B involving twins (2, 2, and 10) is ruled out by the middle son with red hair. The product of both are 40 and the sums are 14. The basis for that solution is as follows: The postman's first statement tells us that x*y*z = A; the postman's second statement tells us that x+y+z = B; and the third statement tells us that x does not equal y does not equal z. We know that the three ages are different because the "middle" son has red hair, which implies that none of the children are twins. The most important piece of information in the puzzle is that there must be at least two sets of numbers that add together to give the same sum and multiply together to give the same product -- or he would have been able to figure it out without the third parameter about the middle child (no twins). Thus, there are two sets of three numbers x1, y1, & z1 and x2, y2, & z2 where x1 + y1 + z1 = x2 + y2 + z2 and x1 * y1 * z1 = x2 * y2 * z2 . It is not the fact that there are no twins, but the fact that the postman could NOT figure out the answer UNTIL he knew that there were no twins that is essential. He needed to know that fact in order to solve the problem, and there must be only two different sets of age choices for the kids (one with twins; one without twins) that produce equivalent A's and B's.

Need a more detailed explanation?

A man is asked what his daughters look like. He answers, "They are all blondes, but two, all brunettes, but two, and all redheads, but two." How many daughters did he have?
 

Reveal Answer

Three: one blonde, one brunette and one redhead.

An old man said to a young man, "I have a daughter. She has as many brothers as she has sisters. Each one of her brothers has twice as many sisters as he has brothers. How many sons and daughters do I have?"
 

Reveal Answer

3 sons and 4 daughters (total of 7 children). The answer to this problem can be found with a little algebra. Let S be the number of sons and D be the number of daughters. From the first statement we have: S=(D-1). From the second statement we have: 2(S-1) = D Solving for S and D gives S=3, D=4, i.e., 4 daughters and 3 sons.

The "he" puzzle:
Name an English word of more than 2 letters that both begins and ends with the letters 'he' (in that order). (Actually, there are two possible correct answers -- and "hehe" is not an acceptable solution.)
 

Reveal Answer

Headache Or heartache

Pill Puzzler
You've been placed on a course of expensive medication in which you are to take one tablet of medicine A and one tablet of medicine B daily. You must be careful that you take just one of each because taking more of either can have serious side effects. Taking an A without taking a B, or vice versa, can also be very serious, because they must be taken together in order to be effective. In summary, you must take exactly one of the A pills and one of the B pills at one time. Therefore, you open up the A bottle, and you tap one A pill into your hand. You put that bottle aside and you open the B bottle. You do the same, but by mistake, two Bs fall into your hand with the A pill. Now, here's the problem. You weren't watching your hand as the pills fell into it, so you can't tell the A pill apart from the two B pills. The pills look identical. They are the same size, same weight, same color, same everything, and they are not marked differently in any way. What are you going to do? You cannot tell which pill is which, and they cost $100 a piece, so you cannot afford to throw them away and start over again. How do you get your daily dose of exactly one A and exactly one B without wasting any of the pills?
(speaking of throwing things away, don't miss our Reduce, Reuse, Recycle tips!)
 

Reveal Answer

CUT EACH OF THE THREE PILLS IN HALF, AND CAREFULLY SEPARATE THEM INTO TWO PILES, WITH HALF OF EACH PILL IN EACH PILE. You do not know which pill is which, but you are 100% sure that each of the two piles now contains two halves of pill B and half of pill A. Now go back into the pill A box, take out a pill, cut it in half, and add one half to each stack. Now you have two stacks, each one containing two halves of pill A, and two halves of pill B. Take one stack of pills today,and save the second stack for tomorrow. And the problem is solved."

Voiceless it cries
wingless flutters
toothless bites
mouthless mutters
 

Reveal Answer

The wind

It cannot be seen,cannot be felt
cannot be heard, cannot be smelt
it lies behind stars and under hills
and empty holes it fills
 

Reveal Answer

Darkness

Alive without breath,
as cold as death,
never thirsty,
ever drinking,
when tired, never winking.
 

Reveal Answer

Fish

Dies half its life
lives the rest
dances without music
breathes without breath
 

Reveal Answer

Trees

I live above a star, and yet I never burn,
I have eleven neighbors, and yet none of them turn,
I am visited in sequence, first, last or in between,
PRS (& sometimes Q)are my initials, now tell me what I mean.
 

Reveal Answer

The "7" key on a telephone keypad. (Note: Newer phones have added the letter "Q" to the initials.)

What is better than the best, more evil than demons, the poor have it and the rich need it, and if you eat it, you will die?
 

Reveal Answer

Nothing

I am one simple word, but I mean different things
One of my meanings brings great forceful swings,
The other of me, may have curve, like the first...
But only one meaning can help quench a thirst.
One of my meanings will often bring cheers,
Either of them could hold a few beers.
 

Reveal Answer

A pitcher.

As I watch I see the world pass me by.
All the good, the bad, in the twinkle of an eye.
I watch and wait, and patiently sit.
I never began, so I shall never quit.
My only presence is in my being.
It is hardly noticed, and not worth a thing.
I'm fast as light, thin as air.
Run if you can. Run if you dare.
To avoid me is the mark of a fool.
For all you're worth, your life is my tool.
Though concealed, I am not shy
The question is: What am I?
 

Reveal Answer

I can see you're confused
by my little rhyme.
Don't fret, my friend.
You have plenty of TIME!
(An original poem/riddle Contributed by Kaaljmirek Kahlia)

What unusual property do the words FLOUR, TERN, and THIRSTY have in common? 
 

Reveal Answer

Remove one letter from each word and they all spell a numeral. Four, Ten, and Thirty

Here's an original brainteaser submitted by an NIEHS scientist:
What six letter word in the English language contains ten other words without rearranging any of its letters?
 

Reveal Answer

The word is "spared". The other words in it are: spa; spar; spare; pa (as in ma and pa); par; pare; pared; are; re (as in do-re-me); and red.

On that same order, what seven letter word in the English language contains ten other words without rearranging any of its letters.
 

Reveal Answer

The word is "therein". The words are: the, there, he, re (as in do, re, mi), in, rein, her, here, ere, herein

You have two fuses (a fuse is something you burn to eventually set off an explosive), one which burns 1 hour and one which burns 2 hours. The fuses do not burn at a constant rate, so, for example, the last few inches of the first fuse could take 5 minutes or 55 minutes to burn. You have as many matches as you want. With these fuses, you have to measure a time period of exactly 45 minutes. How do you do this?
 

Reveal Answer

First light the fuse of 1 hour AT BOTH SIDES AND simultaneously light the fuse of 2 hours AT ONE SIDE. The first fuse will be gone in 0.5 hours. At that time, you light the second end of the fuse of 2 hours: 1.5 hours remain on this fuse. This fuse will now burn in exactly 45 minutes

You have a rope that will reach around the earth (+/- 40,000 km). If you put sticks of 1 meter high around the world and lay the rope on these sticks, how much longer will the rope need to be?
 

Reveal Answer

ONLY 6.28 meter (= 2 PI). And the strange thing is that it even doesn't matter how great the original circle is: it can be 1m, 100m or 1000 km in radius, if you extend the radius by 1 meter, the rope always gets 6.28 meters longer.

Problems in the Elevator: A person lives on the tenth floor of a building. Every day he takes the elevator to go down to the ground floor to go out. When he returns he takes the elevator to the seventh floor and walks up the stairs to reach his apartment on the tenth floor. Only on rainy days does he take the elevator to the tenth floor. He hates the stairs, so why does he do it?
 

Reveal Answer

He is a young man who cannot yet reach higher than the button for the 7th floor. But on rainy days, he can use his umbrella!

You have four unmarked bottles of pills each containing 100 tablets. One bottle of pills is poisoned. The good pills weigh exactly 1 gram a piece. The poisoned ones weigh exactly 1.1 gram a piece. You also have use of a scale, but can only use it one time. How can you determine with certainty which bottle of pills is poisoned?
 

Reveal Answer
  1. Remove 1 pill from Bottle 1
  2. Remove 2 pills from Bottle 2
  3. Remove 3 pills from Bottle 3
  4. Remove 4 pills from Bottle 4
  5. Combine the 10 pills and weight them together
  6. If Bottle 1 has the poisoned pills, the 10 pills will weigh 10.1 grams
  7. If Bottle 2 has the poisoned pills, the 10 pills will weigh 10.2 grams
  8. If Bottle 3 has the poisoned pills, the 10 pills will weigh 10.3 grams
  9. If Bottle 4 has the poisoned pills, the 10 pills will weigh 10.4 grams

And the problem is solved.

You are in a room with 2 doors -- one leads further into the dungeon, one leads to freedom. There are two guards in the room, one at each door. One always tells the truth. One always lies. What one question can you ask one of the guards that will help you pick the door to freedom?
 

Reveal Answer

If you just wanted to determine which one tells the truth and which lies, you would ask: "If I were to ask the other guard whether you always tell the truth, what would he say?" A reply of "no" means you are talking to the truth teller, a reply of "yes" means you are talking to the liar. So since you only have one question to select the right door, you would have to ask "If I were to ask the other guard, which door would he say leads to freedom?" You would then select the door opposite the one he picked.

Here's one for the math wizards: Three companies agree to split the $1,000,000 cost associated with a toxic waste cleanup, as follows: 1) Company A agrees to pay four times the amount of Company B; 2) Company C agrees to pay one-fourth the sum of the amounts paid by Companies A and B. How much will each company pay?
 

Reveal Answer

Let x, y, and z be the amounts paid by Companies A, B, and C respectively. Since the total cost is $1,000,000, we know that x+y+z=1,000,000. From the other two conditions, we have x=4y and z=(x+y)/4 or equivalently, 4z=x+y. Substituting 4z for x+y into the first equation gives 4z+z=1,000,000, 5z=1,000,000 and z=200,000. Of the remaining 800,000 (x+y=800,000), substituting x=4y for x gives 5y=800,000, or y=160,000. Finally x=4y or $640,000. Thus, Company A pays $640,000, Company B pays $160,000 and Company C pays $200,000.


Einstein's Riddle:
Einstein has been widely credited online with the following riddle, and with the claim that 98% of the world could not solve it. But several of our NIEHS scientists were able to solve it, and they said it is not all that hard if you pay attention and are very patient. Give it a try:

There are 5 houses in 5 different colors in a row. In each house lives a person with a different nationality. The 5 owners drink a certain type of beverage, smoke a certain brand of cigar, and keep a certain pet. No owners have the same pet, smoke the same brand of cigar, or drink the same beverage. Other facts:

  1. The Brit lives in the red house.
  2. The Swede keeps dogs as pets.
  3. The Dane drinks tea.
  4. The green house is on the immediate left of the white house.
  5. The green house's owner drinks coffee.
  6. The owner who smokes Pall Mall rears birds.
  7. The owner of the yellow house smokes Dunhill.
  8. The owner living in the center house drinks milk.
  9. The Norwegian lives in the first house.
  10. The owner who smokes Blends lives next to the one who keeps cats.
  11. The owner who keeps the horse lives next to the one who smokes Dunhill.
  12. The owner who smokes Bluemasters drinks beer.
  13. The German smokes Prince.
  14. The Norwegian lives next to the blue house.
  15. The owner who smokes Blends lives next to the one who drinks water.

The question is : WHO OWNS THE FISH?
 

Reveal Answer

Note: The suggested steps to the final answer below are not unique and are just one of several logical approaches that one could take to reach the proper solution. First consider color. The Norwegian lives in the first house (Fact 9), which is next to the blue house (fact 14). >Thus, the second house is blue. The green house is to the left of the white house (Fact 4), which means that the green house must be either the third or fourth house. But the green house cannot be the third (center) house, because the owner of the center house drinks milk (Fact 8) and the owner of the green house drinks coffee (Fact 5). Thus, the fourth house is green and the fifth house is white. Since the Norwegian lives in the first house (Fact 9), and the Brit lives in the red house (Fact 1), the first house must be yellow, leaving the middle house red. Next consider drinks. The owner of the red (third) house is a Brit (Fact 1) who drinks milk (Fact 8). The owner of the green (fourth) house drinks coffee (Fact 5). The Norwegian lives in the yellow (first) house. The Dane drinks tea (Fact 3), and must be the owner of either the blue or white house. But he can't be the owner of the white house. If he were, then the beer-drinking Bluemaster smoker (Fact 12) would have to live in the blue house, making the Norwegian in the yellow house drink water. But that can't be right because.... the water drinker lives next to the owner who smokes Blends, not Bluemaster. Thus, the Dane must live in the blue house, and since the beer-drinking, Bluemasters smoker cannot live in the yellow house (because that owner smokes Dunhill), he must live in the white house, leaving the Norwegian in the yellow house drinking water. Next consider nationality. Only the German and Swede are unaccounted for. The German smokes Prince (Fact 13) and thus must live in the green house, since the owner of the white house smokes Bluemaster. Thus, the Swede must live in the white house. What about cigars? Only Blends and Pall Mall are unaccounted for. The Pall Mall smoker rears birds (Fact 6) and thus cannot live in the blue house, which has horses. Thus, the Pall Mall smoker lives in the red house and the Blends smoker in the blue house. Finally, what about pets? The horse and bird owners have been identified. The Swede keeps dogs as pets (Fact 2), which means dogs are pets in the white house. The Blends smoker lives next to the cat owner, which indicates that cats are the pet in the yellow house. And finally, the only pet left (although it is not even mentioned explicitly in the puzzle) is fish, which are the pets of the coffee-drinking, Prince-smoking German living in the green house. And the problem is solved.


SEND + MORE = MONEY

Each letter in the above equation stands for a different number, and each time the same letter appears, it is the same number. What is the only set of numbers that makes this equation correct? This is a moderately hard one.
 

Reveal Answer

9567 + 1085 = 10652


Pronounced as one letter but written with three, two different letters there are and two only in me. I'm double, I'm single I'm black, blue, and gray. I'm read from both ends and the same either way.
 

Reveal Answer

Eye


What is it that when you take away the whole, you still have some left over?
 

Reveal Answer

Wholesome


We travel much, yet prisoners are, and close confined to boot. With the swiftest horse we keep pace, yet always go on foot.
 

Reveal Answer

Spurs


What is it that goes with an automobile and comes with it; is of no use to it,and yet the automobile cannot move without it?
 

Reveal Answer

Noise


You are a bus driver. At the first stop, 4 people get on. At the second stop, 8 people get on. At the third stop, 2 people get off, and at the last stop, everyone gets off. The question is: What color are the bus drivers eyes?
 

Reveal Answer

Since the riddle starts out by saying you are the bus driver, the answer would be the color of your own eyes.


You and a group of your friends are in the library. One friend says there is a $100 dollar bill hidden between pages 75 and 76 of a book in the library. But you decide not to go and look for it. Why?
 

Reveal Answer

You know that the odd number in a book is ALWAYS on the right and the even number is ALWAYS on the left, so since the page numbers you were given could not be facing each other. Therefore, you know for a fact that the money could not be hidden there.


Where did the other Dollar Go?

Three men check into a hotel, the manager charges them $30 for one room with three beds which they share. The men go to their room and settle in, after a few moments the manager realizes his mistake, he over charged the three men, the room rate was only $25. He sends for the bellhop to return the $5 to the three men. On his way to the room the bellhop realizes that he can't split $5 between 3 men so he decides to give each man $1 and pocket the remaining $2 as a tip. The bellman returns the $1 to each man. In the three mens minds they each paid $9 for the room, or a total of $27, include the $2 tip the bellhop kept and that equals $29, what happened to the other dollar?
 

Reveal Answer

It's a trick on words that leads you to believe the answer is 30 and has you add the number 2 when you should be subtracting as follows: 3 x $9 = 27, then minus the $2 = $25 which is what they paid for the room. And if you take what they ultimately paid for the room ($25) and add the $3 ($1 each they received), and then add the $2 the bellhop took, you would reach the original $30 that was paid.


Six glasses are in a row. The first three are full of juice; the second three are empty. By moving only one glass, can you arrange them so empty and full glasses alternate?
 

Reveal Answer

Pour the juice from the 2nd glass into the 5th glass.


You throw away the outside and cook the inside. Then you eat the outside and throw away the inside. What are you eating?
(speaking of throwing things away, don't miss our Reduce, Reuse, Recycle tips!)

Reveal Answer

An ear of corn.


Why are 1990 American dollar bills worth more than 1989 American dollar bills?
 

Reveal Answer

1990 (1,990) dollar bills are worth $1,990; 1989 (1,989) dollar bills are worth $1,989.


Rearrange the letters in the words "new door" to make one word.
 

Reveal Answer

It can be respelled to read: One Word


What is the largest amount of money in coins you can have without being able to make exact change for a dollar.
 

Reveal Answer

$1.19 -- If you have three quarters, four dimes, and four pennies, you have $1.19, but you still cannot make exact change for a dollar.


What number when multiplied against itself will result in a number which includes the numbers (1 - 9) in forward order, and then descending in order from the 9? (i.e., to get the number: 12,345,678,987,654,321)
 

Reveal Answer

111,111,111 X 111,111,111 = 12,345,678,987,654,321


How many words (in the English language) can you think of that exactly rhyme with each of the words below. The blank boxes beneath each word can be used to type in your answers as you think of them.

Month

Orange

Silver

Purple


 

Reveal Answer

Although debated frequently, most sources say that no word in the English language exactly rhymes with any of those words, but that depends on how strictly you want to interpret "rhyme". For example, some feel that sporange (the bag that contains spores in some types of mushrooms in the field of botany) rhymes with orange. But the popular "Ask Marilyn" column of the newspaper indicated that experts agreed that although the last syllable sounds very similar, neither of the two pronunciations given for sporange in Webster's Third New International Dictionary exactly rhyme with orange. Using www.yourdictionary.com pronunciations, circle may really rhyme with purple! But that wasn't the case for doorhinge/orange or all the other purple rhyming possibilities such as turtle/purple, hurdle/purple, and hurtle/purple.


Historical Teaser:
Where did the common "military salute" get its start?
 

Reveal Answer

Armored knights raised their visors to identify themselves when they rode past their king. This custom has become the modern military salute.


I am periodically the number 79. They once tried to make me from 29. If you add to me 80, I will appear to be 47 temporarily. What am I?
 

Reveal Answer

Gold. On the PERIODIC table of elements, gold is represented by the number 79. Long ago alchemists tried to make it from copper (number 29). If mercury (number 80) comes into contact with gold, It will appear to be silver (number 47) for a while.


Learn more at the Lenntech Periodic Table

What is the longest non-hyphenated word in English in which no letters are repeated (each letter appears only once)?
 

Reveal Answer

UNCOPYRIGHTABLE (15 letters -- or UNCOPYRIGHTABLES, for 16-letters). There are several other long words you might have guessed such as DERMATOGLYPHIC (14 letters) and SUBDERMATOGLYPHIC (17 letters)


What occurs once in a second, once in a minute, twice in a millennium, but never in the course of a lifetime?
 

Reveal Answer

The letter "n".


In the eyes, it causes blindness.
In the nose, it makes sneezes,
But some people seek it out,
And act as though it pleases.
 

Reveal Answer

Smoke or smoking (Remember, smoking is very bad for you and those around you too!)


What has no content, yet you can see it?
 

Reveal Answer

A hole (or a shadow!)


What is bigger when new and grows smaller with use?
 

Reveal Answer

A pencil (or popsicle, sucker, lollipop, etc.)


What do you use to "hoe a row, slay a foe, and wring with woe"?
 

Reveal Answer

Your hands.


John Smith bought a used car for $600 and sold it to Mary Baker for $800. He later bought it back for $1000 and resold it for $1200. How much profit did John make?
 

Reveal Answer

$400.


I am just a lowly thing, object of much derision,
I am odd because I multiply by division.
 

Reveal Answer

An amoeba.


Sometimes it glitters, but often not;
May be cold, or may be hot.
Ever changing though the eye can't measure,
Concealed within may be many treasures.
Some find safety beneath its gate,
While some may die beneath its weight!
Old and broken, it brings forth life.
 

Reveal Answer

A stone. Some stones shine while some don't. At noonday they are hot and at midnight cold. Stones are always getting smaller from wind, heat, and water, but eyes can't measure the change because it is so slow. And they hide things that men find valuable, such as gold and silver. Small creatures find safety beneath a stone, but a stone can also crush life. And when a stone is old and broken into tiny pieces, it becomes part of the soil that gives birth to trees and grass.


What 3-letter word in English has an odd start, an even finish and an infinitely long middle?
 

Reveal Answer

The word "vex." "v" is the Roman numeral for 5, which is odd. "x" is the Roman 10, which is even. "e" is the base of the natural logarithm. It is an irrational number (i.e., e = 2.718281828...) whose mantissa (part to the right of the decimal point) is infinitely long.


I got it in a forest but didn't want it. Once I had it, I couldn't see it. The more I searched for it, the less I liked it. I took it home in my hand because I could not find it. What was it?
 

Reveal Answer

a splinter.


Where can one stand up straight, but still be considered sideways?
 

Reveal Answer

The equator. One would stand up straight with respect to the ground, but be somewhat sideways with respect to the Earth's axis.


At night I come without being fetched. By day tho lost, I'm not really gone. What am I?
 

Reveal Answer

A star.


Which word in the English language is most frequently spelled wrong?
 

Reveal Answer

The word "wrong".


Rearrange the letters in "OWONDER" to make one word.
 

Reveal Answer

"One word"


What runs fore to aft (i.e., front to back) on one side of a ship, and aft to fore (i.e., back to front) on the other side?
 

Reveal Answer

The name of the ship.


Name one eight letter word that has kst in the middle, in the beginning, and at the end.
 

Reveal Answer

"Inkstand" "in" is at the beginning, "kst" is in the middle, and "and" is at the end.


"Think of words ending in -GRY. Angry and hungry are two of them. There are only three words in the English language. What is the third word? The word is something that everyone uses every day. If you have listened carefully, I have already told you what it is."
 

Reveal Answer

"Language" is the third word no, it doesn't end in "gry". We didn't say the third word in "the English language" ends in -gry too. Of course, as in many brainteasers, proper punctuation (i.e., putting "the English language" in quotation marks) would have given the puzzle away.


A clever thief in the olden days was charged with treason against the king and sentenced to death. But the king decided to be a little lenient so he let the thief choose his own way to die. What way should the thief choose?
 

Reveal Answer

To die of old age.


My host thinks I'm an irritation, a bother, a pain.
But he can't evict me, so I stay, remain.
Then one day I'm taken and ranked among my peers.
Can you guess just what I am? Then you might call me dear.
 

Reveal Answer

A pearl.


I can make you lighter, or cause your death. Some are afraid of me, but I'm also loved by many.
 

Reveal Answer

Water.


There is a common English word that is seven letters long. Each time you remove a letter from it, it still remains a common English word -- from seven letters right on down to a single letter. What is the original word, and what are the words that it becomes after removing a letter at a time?
 

Reveal Answer

The word "snowing." It decomposes down to "sowing", "swing", "sing", "sin", "in", and "I".


What falls but never breaks?
 

Reveal Answer

Night.


What breaks but never falls?
 

Reveal Answer

Day.


Part carbon, part water,
I am poison to the fishes.
Many falsely claim my name,
I am the pause that refreshes.
 

Reveal Answer

Soda.


An egg salesman was asked how many eggs he had sold that day. He replied, "My first customer said, 'I'll buy half your eggs and half an egg more'. My second and third said the same thing. When I had filled all three orders, I sold out of eggs without having to break a single egg the whole day." How many eggs were sold in all? Explain this!
 

Reveal Answer

Seven. He sold 4 eggs to the first customer (half of seven is 3 1/2 plus the other half = 4 eggs) 2 to the second person (half of the remaining 3 eggs = 1 1/2, plus the other half = 2) and 1 to the third (half of the remaining egg, plus the other half = 1).


It can be cut and will grow back. Yet when you least expect it, it may disappear never to return.
 

Reveal Answer

Hair.


I'll lap at your heels,
If you give me the chance.
Though I won't fetch or stay,
I surely will dance.
 

Reveal Answer

Fire.


You can see it, but you can't touch it. It may disappear, but has never really left you. It grows throughout the day. What is it?
 

Reveal Answer

Your shadow.


Hi! Ma and Pa told me I'd better say that all the two-letter words in this paragraph have something in common ...... or else! What's the common factor here?
 

Reveal Answer

All the two-letter words are abbreviations of U.S. states (Hawaii=HI, Massachusetts=MA, Pennsylvania=PA, Maine=ME, Idaho=ID, Indiana=IN and Oregon=OR).


You are taking a vacation on an island in the middle of a lake. The lake is in a remote part of Maine and there has never been a bridge connecting the island to the land. Every day a tractor and wagon gives hay rides around the island to all the children. Puzzled as to how the tractor had gotten onto the island, you ask around and find out that the tractor was not transported to the island by boat or by air. Nor was it built on the island. Explain how the tractor may have gotten there?
 

Reveal Answer

It was driven over in winter when the lake was frozen over.


There is a barrel with no lid and some rum in it. "This barrel of rum is more than half full," said Charlie. "No it's not," say Harry. "It's less than half full." Without any measuring implements and without removing any rum from the barrel, how can they easily determine who is correct?
 

Reveal Answer

Tilt the barrel until the rum barely touches the lip of the barrel If the bottom of the barrel is visible, then it is less than half full. If the bottom is still completely covered by the rum, then it is more than half full.


What two words in the English language uses all five vowels plus Y in alphabetical order and uses each one only once?
 

Reveal Answer

"Facetiously" (which means "in a comical, jocular or flippant manner") and abstemiously (which means "eating and drinking moderately, or using only the bare necessities")


By Moon or by Sun, I shall be found; yet I am undone when there's no light around.
 

Reveal Answer

A shadow.


The more you have of it, the less you see. What is it?
 

Reveal Answer

Darkness.


Only one color, but not one size,
Stuck at the bottom, yet easily flies.
Present in sun, but not in rain,
Doing no harm, and feeling no pain.
 

Reveal Answer

A shadow.


Forward I am heavy, but backward I am not. What am I?
 

Reveal Answer

The word 'ton'.


It is in a rock but not in stone,
It is in marrow but not in bone.
It is in a bolster but not in bed.
It's not in the living, and not in the dead.
 

Reveal Answer

The letter "r".


What is nothing, yet has a name? It is sometimes tall and sometimes short. It joins our talks and joins our games, And plays in every sport.
 

Reveal Answer

A shadow.


I know a word of letters three. Add one letter to it and none there will be. What is the word?
 

Reveal Answer

The word "one." Add an "n" and then you have "none."


What is it that has four legs, one head and a foot?
 

Reveal Answer

A bed.


I weaken all men for hours each day. I show you strange visions while you are away. I take you by night, by day take you back, None suffer to have me, but do from my lack.
 

Reveal Answer

Sleep.


They have not flesh nor feathers, nor scales nor bone; but they do have fingers and thumbs of their own.
 

Reveal Answer

Gloves.


Many things can create one. It can be of any shape or size. It is created for various reasons, and it can shrink or grow with time. What is it?
 

Reveal Answer

A hole.


This is an unusual paragraph. I'm curious how quickly you can find out what is so unusual about it? It looks so plain you would think nothing was wrong with it! In fact, nothing is wrong with it! It is unusual though. Study it, and think about it, but you still may not find anything odd. But if you work at it a bit, you might find out! Try to do so without any coaching!
 

Reveal Answer

The letter e, which is the most common letter in the English language, does not ever appear in the paragraph.


More detailed explanation for the Postman Riddle: 

The most important feature to recognize in solving this puzzle is that Postman A needed to know that Postman B did not have twins in order to solve the puzzle. That means that there must be two possible solutions that satisfied the "age in years" and "number of windows" conditions of the problem. He needed to rule out twins to solve the problem. To summarize, there must have been two potential solutions with 3 son's ages having:

(i) equal products (the age condition)

(ii) equal sums (the windows condition)

(iii) one involving twins and one not.

If you really wanted to be fussy, since a house cannot have a fraction of a window, it also means that the ages of the sons must all be in integers (whole numbers) and not involve fractional ages.

The one solution to the problem that satisfies all of these conditions is (1, 5, 8) which has the same sum (14) and the same product (40) as another possible solution involving twins (2, 2, 10). There is just no other solution that works involving a postman's age less than 90 years old. That is, another solution that works mathematically is 2-5-9 and 3-3-10, but that would make the postman 90 years old.

It is a part of us, and then replaced.
It escapes our bodies to a better place.
The world becomes its sizable home.
Its passions unrestrained, the planet it roams.
 

Reveal Answer

Water.

I have a face, yet no senses. Time is of the essence to me, but I do not really care what time it is.
 

Reveal Answer

A clock.

What five letter word would be pronounced the same if its last four letters were removed?
 

Reveal Answer

The word "queue", which is pronounced like "cue". Removing "ueue" leaves "q".

If nine-thousand nine-hundred and nine dollars is written as $9,909, how should twelve-thousand twelve-hundred and twelve dollars be written?
 

Reveal Answer

$13,212.

What are the minimum number of modifications needed to make the equation: 1 + 1 + 1 = 142 true?
 

Reveal Answer

One -- add a slanted line to either one of the "+" signs to make it a "4", thus validating the equation with one modification.

My scale is something that does not weigh in grams, ounces, or pounds. However I may be heavy or light. What am I?
 

Reveal Answer

Music scales.

I am in a place where weight does not exist, and every direction I face is up. Where am I?
 

Reveal Answer

The center of the earth.

Weight in my belly, trees are my back, nails in my ribs, feet I do lack.
 

Reveal Answer

A wooden boat or a ship.

Double my number, I'm less than a score,
Half of my number is less than four.
Add one to my double when bakers are near,
Days of the week are still greater, I fear.
 

Reveal Answer

Six.

What force and strength cannot get through, I with a gentle touch can do.
And many in the street would stand, were I not a friend at hand.
 

Reveal Answer

Key.

For all times it's unchanging, it divides without traces;
it's powers are limited to itself and it's bases.
 

Reveal Answer

The number 1.

What word in the English language, when written, can be turned upside-down to result in an abbreviation of the antonym of the original word?
 

Reveal Answer

The word "up." Write "up" upside down, and you get "dn", the abbreviation of "down", which is the opposite of "up."

What is yours, but is used by others more than yourself?
 

Reveal Answer

Your name. And probably also your address and your phone number!

What does everyone have that goes up, but never comes down.
 

Reveal Answer

Age.

Nearly bright as the sun,
Sometimes dark as space. Like a pearl on black velvet,
with diamonds twinkling in my case.
What am I?
 

Reveal Answer

The moon.

Many many keys I have, but no door I unlock.
Four strong legs and enchanting voice,
Yet I never run or talk.
What am I?
 

Reveal Answer

A piano.

I'm a house with two boarders (sometimes one, but rarely three).
Break my walls, eat my boarders, then throw away the rest of me.
(speaking of throwing things away, don't miss our Reduce, Reuse, and Recycle tips!)
 

Reveal Answer

A peanut.

A truck leaving New York for West Virginia weighs exactly 2 tons. About halfway through the trip, it crosses a bridge with a maximum capacity of 2 tons -- any more weight on it, and the bridge will instantly collapse. Just before the truck crosses the bridge, a 2 pound tree limb falls and lands on the roof of the truck and remains there as the truck crosses the bridge. But the bridge does not collapse. Why?
 

Reveal Answer

The truck weighs 2 tons only at the beginning of the trip. By the time it reaches the bridge (halfway through the trip) it has used up a lot of gas and therefore weighs considerably less than the maximum limit of the bridge. The weight loss is enough to accommodate the extra weight of the tree limb.

Nothing inside, nothing outside, at least that you can see.
I'm as light as a feather, yet ten men can't lift me!
What am I?
 

Reveal Answer

A bubble.

We are five little things of a similar sort. You will find us all on a tennis court.
 

Reveal Answer

The vowels - a, e, i, o and u, which all appear in the phrase "a tennis court".

What makes my left hand, my right?
 

Reveal Answer

A mirror.

What is the only 6-letter word in the English language that gives you 12 when you take away 1?
 

Reveal Answer

Dozens (remove the s, and you have a "dozen", or 12)

Though liquid to start, don't push me too far,
For then I will break, and the damage may scar.
What am I?
 

Reveal Answer

A window or anything made of glass.

A man drove all the way from New York to San Francisco only to discover at the end of the trip that he had a flat tire from the very start. Yet his car was completely unaffected by it? How is this possible?
 

Reveal Answer

It was his spare tire that was flat.

My timpini play a rhythmic song,
With hammer on anvil I play along.
Down my canal no ship sets course,
And I have a stirrup that fits no horse.
What am I?
 

Reveal Answer

An ear.

Past mountain, meadow, field, and hill, it follows a river while standing still.
 

Reveal Answer

A river bank.

I am all that I am and all that you see,
Yet I'm nothing at all and from you I flee.
Formed of distortion, perceptions awry,
I play the horizon where always I lie.
What am I?
 

Reveal Answer

A mirage.

A strange attraction compels me to hold your things most dear, yet I know it not, and feel no warmth in my holding. My brothers and I stick close together until one faces me, and then is pushed away. What am I?
 

Reveal Answer

A magnet.

Throughout history, there have been thousands of well-documented cases of horses jumping over towers and landing on clergy and small men, forcing their removal. When does this bizarre-sounding phenomenon occur?
 

Reveal Answer

In the game of chess this occurs when a knight (i.e., the piece that looks like a horse) "takes" a bishop or a pawn.

"One third of six and two thirds of eleven make seven." Explain why this statement is correct.
 

Reveal Answer

One third of the word "six" is the letter "s", while two thirds of the word "eleven" leaves the word "even". Combining the two gives you "seven".

Name three consecutive days without using the words Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, or Sunday.
 

Reveal Answer

Yesterday, today, and tomorrow.

I am found on land and in sea, yet I neither walk nor swim. I travel by foot, but have no toes. No matter where I roam, I'm never away from home. What am I?
 

Reveal Answer

A snail.

I am made of the stuff around me, but lighter than it. More of me is hidden than seen. What am I?
 

Reveal Answer

An iceberg.

What is always coming but never truly arrives?
 

Reveal Answer

Tomorrow.

I am not alive, but I grow; I don't have lungs, but I need air; I don't have a mouth, and water kills me; What am I?
 

Reveal Answer

Fire.

There is a word in the English language in which the first two letters signify a man, the first three signify a woman, the first four signify a great man, and the whole word represents a great woman. What is the word?
 

Reveal Answer

Heroine.

A shepherd has one wolf, one lamb, and a bundle of grass. He needs to get all three things from one hill to another. He has to prevent the wolf from eating the lamb and the lamb from eating the grass. The hills are connected by a bridge. He can only carry one thing at a time, so he cannot carry all three at the same time. The wolf will not eat the lamb, and the lamb will not eat the grass as long as the shepherd is there. How does he get them across without one eating the other?
 

Reveal Answer

The shepherd should take the lamb first. Then come back for the grass. When he brings the grass to the other hill, he should take the lamb back with him to pick up the wolf. He leaves the lamb on the first hill when he takes the wolf over to the second hill where the grass is. Remember, the wolf and the grass are on the second hill, and the wolf will not eat the grass. Then he can go back and pick up the lamb that he had returned to the first hill. When he takes the lamb back to the second hill, his job is done.

What is black when you buy it, red when you use it, and gray when you throw it away?
(speaking of throwing things away, don't miss our Reduce, Reuse, and Recycle tips!)
 

Reveal Answer

Charcoal.

What do you throw out when you want to use it, but take in when you don't want to use it?
 

Reveal Answer

An anchor.

When can you add 2 to 11 and get 1 as the correct answer?
 

Reveal Answer

When speaking in terms of time -- 2 hours added to 11 o'clock gives you 1 o'clock

You are given three sacks. Each sack has any number of gold pieces of equal size and shape. However, one sack has only pieces of iron pyrite. The pieces of iron pyrite are equal in size and shape and appearance to the gold pieces, but there is a difference in weight between the gold and the fools gold. Let's say that the pyrite weighs one-half ounce and the gold weighs one ounce. The pieces all look essentially identical, so you cannot tell which sack contains iron pyrite by looking at the pieces. You are then handed a scale, and are allowed to take only one measurement in which you weigh pieces from all three sacks simultaneously. You can decide how many pieces from the sacks that you would like to include in the single weighing. How do you prove which sack has the "fool's gold"? Assume that you cannot tell the difference in weight when you are handling the pieces -- you must determine which bag is which only by the total weight reflected on the scale.
 

Reveal Answer

Take one piece from the first bag, two pieces from the second bag, and three pieces from the third bag. Then weigh them. If you get a total of: 5 1/2 ounces= the the first bag had the pyrite (1/2 ounce of pyrite from the first bag, 2 ounces of gold from second bag, and 3 ounces of gold from 3rd bag = 5 1/2 ounces). 5 ounces= then the second bag had the pyrite (one ounce of gold from the first bag, two 1/2 oz. pieces of pyrite from second bag, and 3 ounces of gold from third bag = 5 ounces) 4 1/2 ounces= then the third bag has the pyrite (1 ounce of gold from the first bag, 2 ounces of gold from the second bag, and three 1/2 ounces of pyrite from the third bag = 4 1/2 ounces). You can use this same method to solve the problem regardless of the number of bags involved, or the actual difference in weight.

Apples and Oranges: In the garage behind your house, you have three big boxes. One of the boxes is labeled "Apples", another one "Oranges" and the last one "Apples and Oranges". The only thing you know is that none of the labels is correct! How can you correctly re-label all the boxes, if you are only allowed to take out ONE fruit from ONE of the boxes?
 

Reveal Answer

You take a fruit from the box labeled "apples and oranges". If you pull out an apple, then you should put the "apple" label on that box. If you pull out an orange, then put the "orange" label on that box. Then since you knew all three boxes had incorrect labels, you would switch the remaining two labels as well!

Waiting For A Train: Every day, a wife picks up her husband at the train station at 5:00 p.m. One day he arrives early, at 4:00, and he decides to walk along the same road that his wife will be traveling. She meets him along his way, and takes him home from there. If he had waited at the train station, she would have arrived exactly at 5:00. But having met him along the way, they were able to get home 20 minutes early. So what time was it when she actually picked him up?
 

Reveal Answer

4:50 p.m. (or 10 minutes till 5:00), since she must have saved 10 minutes in both directions.

I know a word of letters three. Add two, and fewer there will be. What word could this be?
 

Reveal Answer

Few has three letters; add two, "er", and you get "fewer".

While exploring the unknown, three scientists get caught by a group of criminals. A game is played to give the scientists an opportunity to go free. In the game, the scientists are tied in a row so that one scientist can see the backs of the other two in front of him, the scientist in the middle can only see the back of the one scientist in front of him, and the one in the very front cannot see any of the others. They are shown five colored feathers, among which there are three white feathers and two black ones. They are blindfolded and each of them is given a feather from the group of five to put in the back of his hair. Then the blindfolds are taken off, and they are asked to call out the color of their own feather as soon as they can tell what it is, without discussing it with the others first. If even one of them can guess the correct color of his feather, all three of them will be released. A little time passes and none of them speaks...then the man bound to the very first stake (who actually can't see anybody) correctly names the color of his own feather. What thoughts lead to his conclusion?
 

Reveal Answer

If the third man (who can see both of the others) had seen two black feathers in front of him, he would have immediately been able to say that he himself must have a white feather (since there are only two black feathers). But he didn't say anything. Given this fact, if the second scientist had seen a black feather in front of him, he would have been able to tell that his feather was white. But he, too, didn't say a word. Therefore the man in front can deduce that his feather is white.

The Family Reunion: At a recent family reunion, the family consisted of 1 grandfather, 1 grandmother, 2 fathers, 2 mothers, 4 children, 3 grandchildren, 1 brother, 2 sisters, 2 sons, 2 daughters, 1 father-in-law, 1 mother-in-law, and 1 daughter-in-law. How many people at the reunion and describe them?
 

Reveal Answer

Seven: 2 little girls, 1 little boy, their mother and father, and their father's father and mother.

Who am I? With thieves I consort, with the vilest in short, I'm quite at my ease in depravity, yet all divines use me and savants can't lose me, for I am at the center of gravity. Who am I?
 

Reveal Answer

The letter "v".

There was once a soldier who had a brother that was wounded in battle. But the wounded man did not have a brother! How could that be?
 

Reveal Answer

The soldier with the wounded brother was a woman. So the wounded soldier had a sister, not a brother!

The maker doesn't want it; the buyer doesn't use it; and the user doesn't see it. What is it?
 

Reveal Answer

Casket (coffin)

A child is born in Boston, Massachusetts to parents who were both born in Boston, Massachusetts. But the child is NOT a United States citizen. How is this possible?
 

Reveal Answer

The child was born before the United States was formed.

What has a mouth but does not speak, has a bed but never sleeps.
 

Reveal Answer

A river.

You can see nothing else when you look in my face
I will look you in the eye and never lie.
 

Reveal Answer

Your reflection in a mirror.

I am so simple that I only point; yet I guide men all over the world.
 

Reveal Answer

A compass

Three times what number is no larger than two times that same number?
 

Reveal Answer

Zero

If three men can chop down three trees in three hours, how many men will it take to chop down six trees in six hours?
 

Reveal Answer

Three men.

What's better than the best thing and worse than the worst thing?
 

Reveal Answer

Nothing.

The day before yesterday Cindy was 17. Next year she will be 20. How can this be?
 

Reveal Answer

The statement was made on January 1. Cindy's birthday is on December 31. She was 17 the day before yesterday (Dec 30). She was 18 yesterday. She will be 19 this year (Dec 31) and 20 next year.

Here is a riddle, I'm happy to say:
This gets larger, the more you take away.
 

Reveal Answer

A hole.

The shape of my form will waver and bend,
From the things I'm destroying and the things I will rend.
My color will vary from bright red and blue,
The power I'm using will dictate my hue.
 

Reveal Answer

A flame.

To some I'm thought beautiful, to others I'm not.
Most times I'm quite round, but sometimes I'm not.
And when I'm not round, I need more attention.
 

Reveal Answer

A mole (on the skin)

A man brought a jeweler six chains that each had five links. He wanted the jeweler to join all six chains together to make one long, closed, circular chain. The jeweler said, "It'll cost you a buck for every link I open and close. You want me to join six chains, so the job will cost you six bucks." "No, no," replied the man, "the job can be done for less." Is he right, and if so, how could it be done?
 

Reveal Answer

It can be done for five dollars. Simply open all five links from one chain and use them to join the remaining chains together.

If 5 dogs can catch 5 cats in 5 minutes, how many dogs will it require to catch 100 cats in 100 minutes?
 

Reveal Answer

It takes five dogs. The rate (one per minute) didn't change, only the number of cats to be caught changed.

AEFHIKLMNTVWXYZ
BCDGJOPQRSU
What rationale is there for the above arrangement?
 

Reveal Answer

Letters formed with only straight lines appear on top, letters with a curve in them are on the bottom.

When can you travel fairly fast,
yet never get far from the first place you passed?
 

Reveal Answer

When swinging!

I do not fly, though some claim I do. I do not stand still, yet it may seem I do. You cannot stop me, no matter how hard you try. What am I?
 

Reveal Answer

Time.

You should keep it after giving it.
 

Reveal Answer

Your word.

What has eight fingers and two thumbs but can't pick up anything by itself?
 

Reveal Answer

A pair of gloves.

Before Mount Everest was discovered, what was the highest mountain on Earth?
 

Reveal Answer

Mt. Everest -- the mountain was still there and was still the highest mountain even though it had not yet been discovered.

Clara Clatter was born on December 27th, yet her birthday is always in the summer. How is this possible?
 

Reveal Answer

She lives south of the equator.

Frank and some of the boys were exchanging old war stories. James offered one about how his grandfather (Captain Smith)led a battalion against a German division during World War I. Through brilliant maneuvers he defeated them and captured valuable territory. Within a few months after the battle he was presented with a sword bearing the inscription:

"To Captain Smith for Bravery, Daring and Leadership, World War One, from the Men of Battalion 8."

Frank looked at James and said, "You really don't expect anyone to believe that yarn, do you?" What is wrong with the story?
 

Reveal Answer

It wasn't called World War One until much later. It was called the Great War at first, because they did not know during that war and immediately afterward that there would be a second World War (WW II)

In what year did Christmas and New Year's fall in the same year?
 

Reveal Answer

Christmas and New Years always fall in the same year; New Year's comes at the first of the year, and Christmas comes near the end of it.

A woman from New York married ten different men from that city, yet she did not break any laws. None of these men died and she was never divorced. How was this possible?
 

Reveal Answer

She was a Justice of the Peace.

Why are 2010 American dollar bills worth more than 2009 American dollar bills?
 

Reveal Answer

$2,010 is one more than $2,009

How many times can you subtract 5 eggs from a carton holding 25 eggs?
 

Reveal Answer

Only once -- after that you are subtracting from a carton that no longer has 25 eggs in it. However, you could again subtract 5 eggs from OTHER cartons of 25 eggs

A taxi driver was called to take a group of passengers to the train station. The station is normally an hour away, but with traffic being extra heavy, it took a full hour and a half. On the return trip the traffic was still as heavy but it took only 90 minutes. Why?
 

Reveal Answer

1 1/2 hours is the same as 90 minutes

How could you rearrange the letters in the words "new door" to make one word? Note: There is only one correct answer.
 

Reveal Answer

"new door" can be rearranged to "one word

Even if they are starving, natives living in the Arctic will probably never eat a penguin's egg. Why not?
 

Reveal Answer

Penguins live in the Antarctic, not the Arctic

Which is correct "The yolk of the egg are white" or "The yolk of the egg is white"?
 

Reveal Answer

Neither -- the yolk is not white, it is yellow

In Okmulgee, Oklahoma, you cannot take a picture of a man with a wooden leg. Why not?
 

Reveal Answer

You can only take pictures with a camera

There were an electrician and a plumber waiting in line for admission to the "International Home Show". One of them is the father of the other's son. How could this be possible?
 

Reveal Answer

One is a man, but the other is a woman, and they are married to each other

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