Case 354
The Stolen Watch
A valuable watch disappeared during a private gathering.
Rule: exactly one suspect is guilty. The guilty suspect lies. Every innocent suspect tells the truth.
Parker
“Either Rowan or Finley is guilty.”
Rowan
“Either Hayden or Peyton is guilty.”
Hayden
“Parker and Peyton are both innocent.”
Peyton
“Neither Parker nor Finley is guilty.”
Finley
“Parker is innocent.”
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.