Someone Stole The Gifts!
Riddle: Miya had a birthday party. She invited three friends over-Derek, Trevor, and Amanda-who each gave her some gifts. In the middle of the party, Miya realizes that someone has stolen all of her gifts. She thinks it is one of the guests, so she questions them. Each guest makes two assertions-one truth and one lie. Derek: "I wasn't in the house when it happened. I know Amanda stole the gifts". Trevor: "Amanda stole them, I saw them. I already have enough gifts". Amanda: "I didn't steal the gifts. Derek tells the truth, he wasn't in the house". Who stole the gifts?
Answer: Trevor stole the gifts. If Derek was the thief, both of his assertions would have been false. And if Amanda was the thief, both of Derek's assertions would have been true. Both cases go against the rules, so Trevor is the thief.
Source: https://www.riddles.com/index.php/11346
