Case 167
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.
Jules
“Either Harper or Morgan is guilty.”
Rowan
“Jules and Harper are both innocent.”
Harper
“Jules and Logan are both innocent.”
Morgan
“Logan is guilty.”
Logan
“Rowan is innocent.”
Who is guilty?
Solution: Morgan
If Morgan is guilty, Morgan's statement is false and every other statement is true. Testing the other suspects creates at least one contradiction.