Case 107
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.
Jordan
“Kendall is innocent.”
Rowan
“Marley is innocent.”
Kendall
“Neither Jordan nor Rowan is guilty.”
Noah
“Either Kendall or Marley is guilty.”
Marley
“Rowan is innocent.”
Who is guilty?
Solution: Noah
If Noah is guilty, Noah's statement is false and every other statement is true. Testing the other suspects creates at least one contradiction.