Case 254
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.
Avery
“Hayden and Jules are both innocent.”
Hayden
“Avery and Jules are both innocent.”
Blake
“Avery is innocent.”
Jules
“Avery and Hayden are both innocent.”
Finley
“Either Blake or Jules is guilty.”
Who is guilty?
Solution: Finley
If Finley is guilty, Finley's statement is false and every other statement is true. Testing the other suspects creates at least one contradiction.