Originally Posted by
Rota
Ten men are about to be executed. They don't like the idea, but they are willing to sacrifice themselves so that others may live. The execution is explained to them. They will be lined up single file, facing the same direction. Each man will be looking at the back of the person in front of him, except for the man in the front of the line. He has noone's back to look at. Each of them will be given a black or white hat on their head. Starting at the back of the line (the man who can see everyone else) they will ask him to state his hat color. If he guesses right, he will be allowed to live. This process continues up the line until each man has been executed or released. The execution is scheduled tomorrow morning. Tonight they must come up with a strategy. How many men can they guarantee will live, and what strategy will ensure this?
There are NOT necessarily five black and five white hats.
Addendum for all of those thinking the first guy can just shout out the hat order and sacrifice himself:
If the men say any word other than "black" or "white," then they are all executed. If the men speak a word at any time other than when they are asked for their own hat color, then all will be executed. If the men say more than that single word in response to the question, then all are executed.