You meet six men on a road side. The problem is that your wallet is mysteriously missing and you can't figure out if these men are truth tellers or not. So you ask a few questions and here are their answers:

Allan: "Fred stole it. Fred also hears quite well."

Barry: "Calvin is a liar. I did not steal it and I know Allan did not steal it."

Calvin: "Allan and Dwayne are both knights. Eddy stole it."

Dwayne: "Allan is a liar. I did not steal it."

Eddy: "Only 4 of us are knights. I did not steal it. I know Calvin did not steal it."

Fred: "I am deaf but read lips. Barry did not steal it."

Who stole the wallet?

P.S. You are sure that all of the men either lie or tell the truth. No one does both.

Calvin says 'Allan and Dwayne are both knights', but then his next statement disagrees with Allan's statement, so Calvin is a liar. This means Eddy did not steal it.

Eddy said he did not steal it, so he is a knight. This means that there are only four knights, and Calvin did not steal it.

Barry says 'Calvin is a liar' so he too is a knight. That means neither he nor Allan stole it.

This means that the person who stole it is either Fred or Dwayne. Fred said that Barry did not steal it, which is true, so he is a knight. That means that Fred really is deaf, so Allan is a liar.

Allan said that Fred stole it, which was a lie. Because there are four knights, that leaves Dwayne to be a knight, so Allan stole it.

So...
Allan = Liar + Thief
Barry = Knight
Calvin = Liar
Dwayne = Knight
Eddy = Knight
Fred = Knight

Posted by Lewis on 2003-06-10 10:15:14