Case 225
The Stolen Prototype
A prototype vanished from a secured workroom.
Rule: exactly one suspect is guilty. The guilty suspect lies. Every innocent suspect tells the truth.
Rowan
“Neither Elliot nor Quinn is guilty.”
Riley
“Either Elliot or Alex is guilty.”
Elliot
“Riley and Quinn are both innocent.”
Alex
“Elliot is guilty.”
Quinn
“Either Rowan or Alex is guilty.”
Who is guilty?
Solution: Alex
If Alex is guilty, Alex's statement is false and every other statement is true. Testing the other suspects creates at least one contradiction.