Case 301
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.
Casey
“Neither Reese nor Rowan is guilty.”
Avery
“Either Casey or Rowan is guilty.”
Reese
“Rowan is innocent.”
Jordan
“Either Casey or Avery is guilty.”
Rowan
“Avery is guilty.”
Who is guilty?
Solution: Avery
If Avery is guilty, Avery's statement is false and every other statement is true. Testing the other suspects creates at least one contradiction.