Professor Z was killed by one of his four students, who was helped by another of the four. His students declared:

A: If B is guilty of something, then C must be innocent.
B: If A is innocent, then C must be guilty.
C: If B was the killer, then D must have had nothing to do with the crime.
D: I am innocent.

As everybody should know, guilty parties always lie, and innocent people always tell the truth. Who killed the professor, and who was his accomplice?

I don't understand how it can be assumed that if a person is lying, that the opposite of his statement is true. Could the deception be on either side of the if...then statement and still be false?

Posted by Jeremy Trenary on 2004-05-28 19:44:56