You meet a trio of people, A, B, and C. You know that one of them is a knight, one is a liar, and one is a normal, but you are not sure which is which. Normals tell the truth and lie at random. You are allowed to ask three yes-or-no questions. What three questions can you ask to find out which is which?
Two players play this game. Numbers from 1 to 9 are layed out in a row. Players take turns putting a coin on one of the numbers that does not yet have a coin on it. Player one puts his coins head-up, and player two -- tails-up.
The winner of this game is the first person to have their coins on three numbers that add up to 15. (For example if a player has coins on 1, 6 and 9, they can win the game by putting a coin on either 8 or 5.)
Is there a strategy for playing this game? Is there a sure-fire way of winning?