Case 313
The Stolen Watch
A valuable watch disappeared during a private gathering.
Rule: exactly one suspect is guilty. The guilty suspect lies. Every innocent suspect tells the truth.
Lane
“Finley and Drew are both innocent.”
Jules
“Finley is guilty.”
Finley
“Neither Lane nor Alex is guilty.”
Drew
“Finley and Alex are both innocent.”
Alex
“Neither Finley nor Drew is guilty.”
Who is guilty?
Solution: Jules
If Jules is guilty, Jules's statement is false and every other statement is true. Testing the other suspects creates at least one contradiction.