You are trapped in a dungeon, and see two doors in front of you. One is a way out, andther will lead to certain death.

Two people are standing in front of these doors, one of them a Knight, another - a Liar. Naturally, you do not know who is who, but they know each other's true nature.

Both the people know which way is correct, but you can only ask one question of one of them before making your choice. What will you ask?

Ask one of them: Are you both Knights?
If he said YES, he is a liar. Then ask the knight the way out.
If he said NO, he is a Knight. Then ask the liar the way out and
take the opposite door.

Posted by Praneeth on 2007-08-29 02:40:36