Case 278
The Missing File
A signed contract file vanished from the archive.
Rule: exactly one suspect is guilty. The guilty suspect lies. Every innocent suspect tells the truth.
Jules
“Either Drew or Kendall is guilty.”
Drew
“Jules is innocent.”
Harper
“Neither Drew nor Noah is guilty.”
Noah
“Drew and Harper are both innocent.”
Kendall
“Noah is guilty.”
Who is guilty?
Solution: Kendall
If Kendall is guilty, Kendall's statement is false and every other statement is true. Testing the other suspects creates at least one contradiction.