Riddle: You are going through a maze when you suddenly come to the end. At the end there are two doors, one leads to you exiting the maze and the other leads to certain death. In front of the doors are two identicle twins (one in front of the exit and one in front of the death door). One of the twins (not knowing which one) always lies, the other (not knowing which one) always tells the truth. What is the one yes or no question that you can ask the twins so you know not only who the lier is, but also which door is the exit?
Answer: If I were to ask your brother if your door was the exit, what would he say that you would say?