Case 115
The Cut Cable
A network cable was cut in a restricted room.
Rule: exactly one suspect is guilty. The guilty suspect lies. Every innocent suspect tells the truth.
Alex
“Sam is innocent.”
Jules
“Alex and Sam are both innocent.”
Quinn
“Either Jules or Kai is guilty.”
Sam
“Kai is innocent.”
Kai
“Jules and Sam are both innocent.”
Who is guilty?
Solution: Quinn
If Quinn is guilty, Quinn's statement is false and every other statement is true. Testing the other suspects creates at least one contradiction.