Brainteaser: In a town, every inhabitant either always tells the truth or always lies. You come to a fork in the road and need to find the way to the village. There are two individuals at the fork. You can ask one question to one of them. What single question can you ask to ensure you find the way?
Answer: Ask either individual “If I asked the other person which way leads to the village, what would they say?” and then take the opposite path. This works because whether you ask a liar or a truth-teller, they will both point to the wrong road, so you can safely choose the opposite.