Case 233
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
“Either Frankie or Blake is guilty.”
Jules
“Neither Frankie nor Blake is guilty.”
Dakota
“Neither Jules nor Blake is guilty.”
Frankie
“Either Rowan or Dakota is guilty.”
Blake
“Neither Dakota nor Frankie is guilty.”
Who is guilty?
Solution: Rowan
If Rowan is guilty, Rowan's statement is false and every other statement is true. Testing the other suspects creates at least one contradiction.