Case 351
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.
Harper
“Kendall is innocent.”
Sam
“Kendall is guilty.”
Kendall
“Neither Peyton nor Frankie is guilty.”
Peyton
“Neither Harper nor Frankie is guilty.”
Frankie
“Sam is guilty.”
Who is guilty?
Solution: Sam
If Sam is guilty, Sam's statement is false and every other statement is true. Testing the other suspects creates at least one contradiction.