Puzzles/Logic puzzles/Knights, Knaves & Spies II

Puzzles | Logic puzzles | Knights, Knaves & Spies II

We have three people one of whom is a knight, one a knave, and one a spy. The knight always tells the truth, the knave always lies, and the spy can either lie or tell the truth. The three persons are brought before a judge who wants to identify the spy.

A says: "I am not a spy." B says: "I am a spy." Now C is in fact the spy. The judge asks him: "Is B really a spy?"

Can C give an answer so that he doesn't convict himself as a spy?

Solution