#12

You are in a hallway and there are two doors. One door leads to heven the other leads to hell. There is a man at each door and both know which door leads to heaven or hell. Youcan ask them any question to find out which door leads to heaven or hell, but one man always lies and the other always tells the truth. Now what question could you ask too find out which door leads to heaven or hell.

Answer:

You go to one man and ask"If I were to ask that guy over there which door leads to heaven what would he say." Then you ask the other guy the same question.