Given the guard’s two options, come up with a tricky statement that, whether it’s true or false, goes against the two choices.
Let me introduce you: Hello Logic, this is the reader. Hello reader, this is Logic. Now that you’ve met, put it to work. The sentence “You will call the police” is true only if he actually calls the police after that. The sentence “You will hit me” is true only if he actually hits you after that. But one of these two statements is self-contradictory. It can’t be true or false given the guard’s choices.
The answer is “You will hit me.” If it’s true, he must call the police and not hit you — which makes it false. If it’s false, he must hit you — which makes it true.
