Case 007
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.
Dakota
“Neither Alex nor Emery is guilty.”
Morgan
“Either Kai or Alex is guilty.”
Kai
“Either Alex or Emery is guilty.”
Alex
“Emery is innocent.”
Emery
“Neither Dakota nor Alex is guilty.”
Who is guilty?
Solution: Kai
If Kai is guilty, Kai's statement is false and every other statement is true. Testing the other suspects creates at least one contradiction.