You are on a treasure hunt, wondering where the "Truth Treasure" is buried. You have no idea where it is buried, so you go Truth Town (made up of only Liars and Knights) because it is famous for holding the treasure's secret location.
When you enter the city, you see two twins and they know each other's types, but you don't. One twin says "(Exactly) one of us is a Knight..." and the other twin says "...and (exactly) one of us is a Liar." You can only ask one question and only to one person. You only care about where the treasure is kept, and obviously a liar would give you a wrong answer, so what should you do?
(In reply to re: Solution - Not convinced
From the word "possibly" in "what answer could he possibly give me?", Twin B the Liar could say w, x or y, if the location was z, so Twin A would be telling the truth if he gave any of those.
If Twin A were allowed to reply, "Twin B could say any of w, x, y or z", then he would be lying without giving away the location. So the question could be rephrased "What is one answer he could possibly give me ?"
Posted by Penny
on 2005-07-05 12:00:13