Case 336
The Missing Ledger
A confidential ledger disappeared from the office.
Rule: exactly one suspect is guilty. The guilty suspect lies. Every innocent suspect tells the truth.
Peyton
“Kai is innocent.”
Finley
“Either Kai or Drew is guilty.”
Parker
“Finley is guilty.”
Kai
“Peyton and Drew are both innocent.”
Drew
“Parker and Kai are both innocent.”
Who is guilty?
Solution: Finley
If Finley is guilty, Finley's statement is false and every other statement is true. Testing the other suspects creates at least one contradiction.