Riddles

[EpicFailOlympian]

89? Horray for "Happy Numbers"!!!
What has a mouth but cannot eat what moves but has no legs and what has a bank but cannot put money in it?

[ichaelm]

Is it a river?

I'll post one that I just heard from one of my friends.

10 men are exploring a cave when suddenly a giant blocks the entrance. He captures them all and puts them in a cage. He tells them that the next morning, he will have them all play a game for their lives. They will all stand in a straight line. Each man will be facing the man in front of him, except of course for the one in front. The giant will place a hat on each of their heads. Each hat is either black or white. The giant may arrange the hats however he wants. Then, he will walk down the line, starting with the man in the back, and ask each one what the color of his hat is. He can only say one word: black or white. If he is wrong, he will be killed. If he is right, the giant will use sorcery to immediately teleport him out of the cave. During the game, none of the dwarfs may turn their heads, and they cannot communicate at all except for that single word when the giant reaches them. The men only have one night to plan their strategy. What is the best strategy they could possibly use, that would ensure the greatest number of lives saved?

Apparently this one was supposed to be super hard, but I got it in a couple minutes So I'm not exactly sure how hard it really is.

[brobo]

Its really simple. The person at the back can see everyone, so he knows what hat he has on. Then the next person, hearing what hat the last person has on, can deduce what color hat he has on, and so on. Here's a harder version of that puzzle:

A man goes around the world and captures the four smartest people. He then places them in front of a wall in the following way: Man 1 faces one side of the wall. Man 2 faces the other side of the wall. Man 3 faces Man 2's back, and Man 4 faces Man 3's back in such a way: 1> |Wall| <2 <4 The arrows show which way they are facing. The man who kidnapped them then places either a black or red hat on each person, as followes: R |Wall| B R B The hat colors correspond to the first "diagram." Everyone knows that there are 2 red hats and 2 black hats. The man who kidnapped them then gives everyone the following instructions:
"You may not communicate in any manor. If you do, everyone will be killed."
"If you cheat by looking at your hat, everyone will be killed."
"If you turn around or look in any direction other than straight forward, everyone will be killed."
"If no one can correctly figure out the color of their hat in two minutes, everyone will be killed."
"If even one person can figure out the color of their hat, everyone will live."

After a minute and a half, someone correctly shouted out the color of their hat. Who was it, and how did they figure it out?


I hope I was clear enough, I'll answer any questions anyone has.

[ichaelm]

Its really simple. The person at the back can see everyone, so he knows what hat he has on. Then the next person, hearing what hat the last person has on, can deduce what color hat he has on, and so on. Here's a harder version of that puzzle:

A man goes around the world and captures the four smartest people. He then places them in front of a wall in the following way: Man 1 faces one side of the wall. Man 2 faces the other side of the wall. Man 3 faces Man 2's back, and Man 4 faces Man 3's back in such a way: 1> |Wall| <2 <4 The arrows show which way they are facing. The man who kidnapped them then places either a black or red hat on each person, as followes: R |Wall| B R B The hat colors correspond to the first "diagram." Everyone knows that there are 2 red hats and 2 black hats. The man who kidnapped them then gives everyone the following instructions:
"You may not communicate in any manor. If you do, everyone will be killed."
"If you cheat by looking at your hat, everyone will be killed."
"If you turn around or look in any direction other than straight forward, everyone will be killed."
"If no one can correctly figure out the color of their hat in two minutes, everyone will be killed."
"If even one person can figure out the color of their hat, everyone will live."

After a minute and a half, someone correctly shouted out the color of their hat. Who was it, and how did they figure it out?


I hope I was clear enough, I'll answer any questions anyone has.

How does he know what hat he has on if he can see everyone else's hat?

EDIT: Are you thinking there are 5 of each color? Not necessarily...

[brobo]

Oh, ok, then here's another solution:
The back person has a 50-50 chance of living. He calls out what color hat the person in front of him has on. That person lives. The next person does the same thing, and so on, every other person having a 50-50 chance of living, while the others have 100% of living.

[ichaelm]

Good, but there's a better way...

[ichaelm]

Hint: you can save at least nine of them!

[ophiophagus]

guess to robodudes: The person who gets it is either person 3 or 4. Person 4 can see the hats of persons 3 and 4, if these two hats are the same color, he will know he is the other color hat and he will yell it out. If he sees that they are different, he will remain silent. Person 3 can see the hat of person 2, and if person 4 remains silent, he will know he has the opposite hat as person2 and he will yell out his hat color.

[paleonaps]

ichaelm (Click to Show Hidden Text)

The man taps the man in front if he is wearing black, and doesn't if he is wearing white.

[ichaelm]

ichaelm (Click to Show Hidden Text)

The man taps the man in front if he is wearing black, and doesn't if he is wearing white.

Nice try, remember: no communication! Except for the one word when the giant gets to each person.