Prince X was trying to save Princess Y who was imprisoned in a castle, he needed to enter the castle. At the entrance, there were two boxes. One of the boxes contained the key while the other did not.
They each displayed a message: box A's message was "this box has the key", box B's message was "this box doesn't have the key". You know that either one or both of the messages was lying.
Which box contained the key?
They each displayed a message: box A's message was "this box has the key", box B's message was "this box doesn't have the key". You know that either one or both of the messages was lying.
Which box contained the key?