Case 095
The Lost Access Card
A master access card was taken from the reception desk.
Rule: exactly one suspect is guilty. The guilty suspect lies. Every innocent suspect tells the truth.
Kendall
“Elliot and Peyton are both innocent.”
Elliot
“Kendall and Peyton are both innocent.”
Taylor
“Either Elliot or Kai is guilty.”
Kai
“Elliot is innocent.”
Peyton
“Either Kendall or Taylor is guilty.”
Who is guilty?
Solution: Taylor
If Taylor is guilty, Taylor's statement is false and every other statement is true. Testing the other suspects creates at least one contradiction.