A Fork in the Road

RAY: Here's the question I would ask. I would look at one of the guys and say, "If I were to ask the other guy which road takes me to the dock, what would he say?"

If you ask the truth teller, it's pretty simple, right? The truth teller will say the liar is going to tell you to take this road, which is -- which is obviously the wrong road because that guy's what?

TOM: He's a liar.

RAY: Right. Now you ask the liar the same question, and he has to point to the same road—because otherwise he'd be telling the truth. Do we have a winner?

TOM: We do! Congratulations to our winner, Elizabeth Caprini from Naples, New York.

[ Car Talk Puzzler ]