Case 295
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.
Dakota
“Lane is innocent.”
Lane
“Dakota is innocent.”
Frankie
“Drew is guilty.”
Casey
“Neither Lane nor Frankie is guilty.”
Drew
“Either Lane or Casey is guilty.”
Who is guilty?
Solution: Drew
If Drew is guilty, Drew's statement is false and every other statement is true. Testing the other suspects creates at least one contradiction.