"Pre-School" Test for you:
Which way is the bus below traveling...toward the left or the right?
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!
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?
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?
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?
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?
Good at math? Try this one.... 1=3
So what does
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?
What are the science teacher's favorite states?
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?
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?
|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?|
- The speed of the rowers is as follows:
- Rower #1 -- rows in 1 minute
- Rower #2 -- rows in 2 minutes
- Rower #5 -- rows in 5 minutes
- Rower #10 -- rows in 10 minutes
- All four people must get to the other side of the river using the rowboat
- Only two people can travel in, on, or around the boat at any one time.
- The person in the boat who rows at the slowest speed must do the rowing (they travel at the speed of the slowest person).
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:
- One of them calls out -- which one called out?
- How can he be 100% certain of the color of his hat?
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.
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.
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?
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?
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?"
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.)
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!)
Voiceless it cries
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
Alive without breath,
as cold as death,
when tired, never winking.
Dies half its life
lives the rest
dances without music
breathes without breath
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.
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?
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.
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?
What unusual property do the words FLOUR, TERN, and THIRSTY have in common?
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?
On that same order, what seven letter word in the English language contains ten other words without rearranging any of its letters.
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?
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?
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?
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?
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?
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?
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:
- The Brit lives in the red house.
- The Swede keeps dogs as pets.
- The Dane drinks tea.
- The green house is on the immediate left of the white house.
- The green house's owner drinks coffee.
- The owner who smokes Pall Mall rears birds.
- The owner of the yellow house smokes Dunhill.
- The owner living in the center house drinks milk.
- The Norwegian lives in the first house.
- The owner who smokes Blends lives next to the one who keeps cats.
- The owner who keeps the horse lives next to the one who smokes Dunhill.
- The owner who smokes Bluemasters drinks beer.
- The German smokes Prince.
- The Norwegian lives next to the blue house.
- The owner who smokes Blends lives next to the one who drinks water.
The question is : WHO OWNS THE FISH?
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.
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.
What is it that when you take away the whole, you still have some left over?
We travel much, yet prisoners are, and close confined to boot. With the swiftest horse we keep pace, yet always go on foot.
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?
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?
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?
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?
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?
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!)
Why are 1990 American dollar bills worth more than 1989 American dollar bills?
Rearrange the letters in the words "new door" to make one word.
What is the largest amount of money in coins you can have without being able to 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)
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.
Where did the common "military salute" get its start?
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?
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)?
What occurs once in a second, once in a minute, twice in a millennium, but never in the course of a lifetime?
In the eyes, it causes blindness.
In the nose, it makes sneezes,
But some people seek it out,
And act as though it pleases.
What has no content, yet you can see it?
What is bigger when new and grows smaller with use?
What do you use to "hoe a row, slay a foe, and wring with woe"?
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?
I am just a lowly thing, object of much derision,
I am odd because I multiply by division.
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.
What 3-letter word in English has an odd start, an even finish and an infinitely long middle?
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?
Where can one stand up straight, but still be considered sideways?
At night I come without being fetched. By day tho lost, I'm not really gone. What am I?
Which word in the English language is most frequently spelled wrong?
Rearrange the letters in "OWONDER" to make 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?
Name one eight letter word that has kst in the middle, in the beginning, and 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."
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?
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.
I can make you lighter, or cause your death. Some are afraid of me, but I'm also loved by many.
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?
What falls but never breaks?
What breaks but never falls?
Part carbon, part water,
I am poison to the fishes.
Many falsely claim my name,
I am the pause that refreshes.
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!
It can be cut and will grow back. Yet when you least expect it, it may disappear never to return.
I'll lap at your heels,
If you give me the chance.
Though I won't fetch or stay,
I surely will dance.
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?
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?
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?
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?
What two words in the English language uses all five vowels plus Y in alphabetical order and uses each one only once?
By Moon or by Sun, I shall be found; yet I am undone when there's no light around.
The more you have of it, the less you see. What is it?
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.
Forward I am heavy, but backward I am not. What am I?
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.
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.
I know a word of letters three. Add one letter to it and none there will be. What is the word?
What is it that has four legs, one head and a foot?
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.
They have not flesh nor feathers, nor scales nor bone; but they do have fingers and thumbs of their own.
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?
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!
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.
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