Case 094
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.
Rowan
“Marley is innocent.”
Marley
“Cameron is innocent.”
Morgan
“Either Rowan or Finley is guilty.”
Finley
“Rowan is innocent.”
Cameron
“Neither Marley nor Finley is guilty.”
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.