Here it is:
An irregular shaped bottle full of beer. A guy starts to drink the beer from the bottle. How can he find out that he drinks exactly half bottle of beer without any assistance? (No spitting out or back into the bottle, that's the mostly asked question when I give the problem to other people. :P)
Here is another one, a very good one, but I didn't solve it myself, which makes me feel very stupid about myself.
A captain wants to shoot all his 10 soldiers. But he wants to have an excuse to shoot them all. So he gives each soldier a hat, the hat can be either black color or white color. He told the soldiers that they need to stand in a straight line, one after another. The person can only see the people in front of him, but not the people behind him. Then he will ask each one what color of the hat the soldier wears, starting from the last guy (who stands in the last and who can see all other 9 hats). If the soldier answers correct, he would be saved, otherwise, he would be shot by the captain. Then the captain will ask the next guy, so on and so forth. All the soldiers can only answer one word, either white or black. But one soldier is very smart, he thinks of a solution, which can maximize the people who will give the correct answer. What is the solution?
Run away
