Black and White Hats Cannibals ambush a safari in the jungle and capture three men. The cannibals give the men a single chance to escape uneaten. The captives are lined up in order of height, and are tied to stakes. The man in the rear can see the backs of his two friends, the man in the middle can see the back the man in front, and the man in front cannot see anyone. The cannibals show the men five hats. Three of the hats are black and two of the hats are white. Blindfolds are then placed over each man's eyes and a hat is placed on each man's head. The two hats left over are hidden. The blindfolds are then removed and it is said to the men that if one of them can guess what color hat he is wearing they can all leave unharmed. The man in the rear who can see both of his friends' hats but not his own says, "I don't know". The middle man who can see the hat of the man in front, but not his own says, "I don't know". The front man who cannot see ANYBODY'S hat says "I know!" How did he know the color of his hat and what color was it?
Transcript
Black and White Hats
Cannibals ambush a safari in the jungle and capture three men. The cannibals give the men a single chance to escape uneaten.
The captives are lined up in order of height, and are tied to stakes. The man in the rear can see the backs of his two friends, the man in the middle can see the back the man in front, and the man in front cannot see anyone. The cannibals show the men five hats. Three of the hats are black and two of the hats are white.
Blindfolds are then placed over each man's eyes and a hat is placed on each man's head. The two hats left over are hidden. The blindfolds are then removed and it is said to the men that if one of them can guess what color hat he is wearing they can all leave unharmed.
The man in the rear who can see both of his friends' hats but not his own says, "I don't know". The middle man who can see the hat of the man in front, but not his own says, "I don't know". The front man who cannot see ANYBODY'S hat says "I know!"
How did he know the color of his hat and what color was it?
The man in front knew he was wearing a black hat because he knew the first man did not see two white hats and he knew that the second man did not see one white hat because if he saw a white hat, the second man would have known that his hat was black from hearing the first man's statement.
Burning Island
A man is stranded on an island covered in forest.
One day, when the wind is blowing from the west, lightning strikes the west end of the island and sets fire to the forest. The fire is very violent, burning everything in its path, and without intervention the fire will burn the whole island, killing the man in the process.
There are cliffs around the island, so he cannot jump off.
How can the man survive the fire? (There are no buckets or any other means to put out the fire)
The man picks up a piece of wood and lights it from the fire on the west end of the island.
He then quickly carries it near the east end of he island and starts a new fire. The wind will cause that fire to burn out the eastern end and he can then shelter in the burnt area.
Crates of Fruit
You are on an island and there are three crates of fruit that have washed up in front of you. One crate contains only apples. One crate contains only oranges. The other crate contains both apples and oranges.
Each crate is labeled. One reads "apples", one reads "oranges", and one reads "apples and oranges". You know that NONE of the crates have been labeled correctly - they are all wrong.
If you can only take out and look at just one of the pieces of fruit from just one of the crates, how can you label ALL of the crates correctly?
Take a piece of fruit from the "apples and oranges" crate. If it's an apple then you know that is the "apples" crate since ALL THE CRATES ARE LABLED INCORRECTLY. This means the crate marked "apples" must be "oranges" and the crate marked "oranges" must be "apples and oranges".
Cut Cube
A solid, four-inch cube of wood is coated with blue paint on all six sides.
Then the cube is cut into smaller one-inch cubes.
These new one-inch cubes will have either three blue sides, two blue sides, one blue side, or no blue sides. How many of each will there be?
There are 24 with one side colored, 8 with three sides colored, 24 with two sides colored, and 8 with no sides colored.
Deadly Choice Puzzle – Solution
A man is caught on the King's property. He is brought before the King to be punished.
The King says, "You must give me a statement. If it is true, you will be eaten by the lions. If it is false, you will be trampled by the wild buffalo."
But in the end, the King has to let the man go.
What was the man's statement?
"I will be trampled by the wild buffalo."
If you think about it carefully: the King can't say that it is true, because if it is then the man should be eaten by the lions. But if he is eaten by the lions, then his statement would be false, and so should have been trampled by buffalo.
Farmer Crosses River
A farmer wants to cross a river and take with him a wolf, a goat, and a cabbage. There is a boat that can fit himself plus either the wolf, the goat, or the cabbage. If the wolf and the goat are alone on one shore, the wolf will eat the goat. If the goat and the cabbage are alone on the shore, the goat will eat the cabbage.
How can the farmer bring the wolf, the goat, and the cabbage across the river?
So the King can't tell if it is a lie or truth, so decides to just let him go.
Farmer takes Goat across (leaving Wolf and Cabbage behind)Farmer returns aloneFarmer takes Wolf acrossFamer returns with Goat
* We now have the Farmer, the Cabbage and the Goat on one side and the Wolf on the other side
Farmer takes Cabbage acrossFarmer returns aloneFarmer takes Goat across
DO
Four Adventurers and a Small Canoe
Four adventurers (Alex, Brook, Chris and Dusty) need to cross a river in a small canoe.
The canoe can only carry 100kg.
Alex weighs 90kg, Brook weighs 80kg, Chris weighs 60kg and Dusty weighs 40 kg, and they have 20kg of supplies.
How do they get across?
Knights and Knaves
There are three people (Alex, Brook and Cody), one of whom is a knight, one a knave, and one a spy.
The knight always tells the truth, the knave always lies, and the spy can either lie or tell the truth.
Alex says: "Cody is a knave."Brook says: "Alex is a knight."Cody says: "I am the spy."
Who is the knight, who the knave, and who the spy?
Girl and Boy
A boy and a girl are talking.
"I am a boy" - said the child with black hair.
"I am a girl" - said the child with white hair.
At least one of them lied. Who is the boy and who is the girl?
They both lied.
The child with the black hair is the girl, and the child with the white hair is the boy.
(If only one lied they would both be boys or both be girls)
Puzzle: 24 from 8,8,3,3
How can I get the answer 24 by only using the numbers 8,8,3,3.
You can use the main signs add, subtract multiply and divide.
8/(3-(8/3))
5-digit Number
What 5-digit number has the following features:
If we put the numeral 1 at the beginning, we get a number three times smaller than if we put the numeral 1 at the end of the number.
Using an easy equation:
3(100000 + x) = 10x+1
(Why? Well, adding 100000 puts a 1 at the front of a five-digit number, and multiplying by 10 and adding 1 puts a 1 at the end of a number)
"The day before yesterday I was only 25 and next year I will turn 28."
This is true only one day in a year - when was he born?
e answer is 42857.
Where Did the Dollar Come From?
Two friends have a nice meal together, and the bill is $25
The friends pay $15 each, which the Waiter gives to the Cashier
The Cashier hands back $5 to the Waiter
The Waiter keeps $3 as a tip and hands back $1 each
So, the friends paid $14 each for the meal, for a total of $28. The Waiter has $3, and that makes $31. Where did the other dollar come from?
$25 is sitting with the Cashier, $2 with the friends, and $3 with the Waiter. That adds to the required $30.
The mistake is expecting that what the men paid and what the Waiter kept to add up to what the men initially gave. In fact, it is the amount that the meal effectively cost them, plus the amount they received back, that should add to $30.
