Case 057
The Lost Access Card
A master access card was taken from the reception desk.
Rule: exactly one suspect is guilty. The guilty suspect lies. Every innocent suspect tells the truth.
Avery
“Either Rowan or Jordan is guilty.”
Drew
“Avery and Jordan are both innocent.”
Rowan
“Either Avery or Drew is guilty.”
Cameron
“Neither Avery nor Jordan is guilty.”
Jordan
“Neither Avery nor Cameron 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.