The islander who called them both liars
On an island where each resident is either a truth-teller (always honest) or a liar (always dishonest), you meet two people, Mo and Ned. Mo speaks up:
Mo: "The two of us are both liars."
Is Mo a truth-teller or a liar? What about Ned?
Your answer
This one is open-ended. Work it through, then check your reasoning against the full solution.