brain benders...

[Bube]

Here's one of my favorites:

A king asks 10 men in his land to bring him 10 gold coins each, each weighing 10 grams. The men all bring the gold, but his vizier tells him that one man has cheated. His gold weighs 9 grams. The king is trying to find the cheater. But he has only one chance to use a scale. He has to find the cheater in one move. How would he do that?

And another one:

There are three people and 5 hats: 3 red, 2 white. Somebody puts all 3 red hats on their heads. Noone can see the hat on their head, and they're asked to guess what color hat they're wearing. The first says that he can't guess. The second one doesn't know as well. But the third says that his is red. How does he know?

And another one:

A prisoner is abandoned on an island in the shape of an oval. He's going to be executed in a different way: His captives will set the trees on the island on fire from one end. And naturally, all the tress will be burned, as will the man. The man has only a lighter. How does he escape?

Another:

3 people. 3 black, 2 white hats. They stand in line, all facing the same way. The hats are randomly placed on their heads. The one at the back can see the other two's hats, the 2nd can see the first one's hat. The 3rd one says that he doesn't know the color of his hat. The second one thinks for a moment and says that he doesn't know as well. The 1st in line says that he knows the color of his hat. What color is it?

Those will keep you busy for a while...