Question: There are 3 chests, labelled food, beds and food and beds.True enough, one chest contains only food, one chest contains only beds and one chest contains both. You are warned that the chests' labels may be lying collectively, or not at all. How can you tell which chest contains what by just opening one of them?
Answer: Open any chest. If its content matches its labels, that means the others will also hold their respective content. If any other chest labels are lying, the rest would also have to hold the items that are not on their label.
Question: A man is found dead on a Sunday morning. His wife calls the police immediately. The police question the wife and staff. The wife said she was asleep, the cook said he was cooking breakfast, the gardener said she was picking vegetables, the butler said he was cleaning the closet, and the maid said she was getting the post. The police immediately arrested the murderer.Who was the murderer?
Answer: The maid because there's no post on Sundays.