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?
(In reply to re: Puzzle Solution
True. The query as posited to both the individuals (in terms of my previous post) would indeed elicit an untrue response from each.
It was a typographical error on my part.
The relevant query to be posited before each of the two individuals should have been:
"If I asked you whether that door would lead to freedom, would you say "yes"?"
Both the Knight and the Liar would be forced to tell the truth in that situation, allowing the prisoner to correctly choose the door leading to freedom.
Edited on May 21, 2007, 11:42 am