There was a crime, and it was known that either Al, Beth, Dell, or Phil (each a knight or a liar) was guilty. At the trial, the men spoke first, and said:

Phil: Dell did it.
Al: No, Beth is guilty.

Then it was the ladies' turn, who said:

Beth: Al is lying.
Dell: Phil never lies.

Then a lady accused someone, and that let me know she herself was innocent.

And next the other lady accused someone, and that let me know who was guilty.

Who's guilty?

Beth was guilty.

Posted by K Sengupta on 2023-01-11 00:39:39