Case 307
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.
Kai
“Neither Logan nor Cameron is guilty.”
Logan
“Emery is guilty.”
Emery
“Either Kai or Logan is guilty.”
Cameron
“Lane is innocent.”
Lane
“Logan is innocent.”
Who is guilty?
Solution: Emery
If Emery is guilty, Emery's statement is false and every other statement is true. Testing the other suspects creates at least one contradiction.