Two thieves have being working together for years. Nobody knows their identities, but one is known to be a Liar and the other a Knave. The local sheriff gets a tip that the bandits are about to commit another crime. When the sheriff arrives at the seen of the crime, he finds three men, A, B, and C. C has been stabbed with a dagger. He cries out, “A stabbed me” before anybody can say anything else; then, he falls down dead from the stabbing.

Not sure which of the three men are the crooks, the sheriff takes the two suspects to the jail and interrogates them. He gets the following information.

A’s statements:
1. B is one of the crooks.
2. B’s second statement is true.
3. C was telling the truth.

B’s statements:
1. A killed the other guy.
2. C was killed by one of the thieves.
3. C’s next statement would have been a lie.

C’s statement:
1. A stabbed me.

The sheriff knows that the murderer is among these three people. Who should the sheriff arrest for killing C?

I probably solved this the slow way.

Ignoring the statements, I get 18 possible scenarios assuming the non-thief can be knight, liar or knave.

With the statements, by process of elmination for each scenario, I only get 1 of these to work out.

A is the Lying Thief
C is the Knave Thief (FTF)
B is a Lying non-thief

B is the killer

Posted by Mike on 2006-03-03 17:48:22