Case 182
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.
Parker
“Logan is guilty.”
Jordan
“Reese is innocent.”
Logan
“Parker is guilty.”
Reese
“Either Parker or Logan is guilty.”
Casey
“Parker and Jordan are both innocent.”
Who is guilty?
Solution: Logan
If Logan is guilty, Logan's statement is false and every other statement is true. Testing the other suspects creates at least one contradiction.