Come up with a question and reasoning that would justify this answer: 15
The question is: Miggy's mom brought home 3 bags of birthday hats. Each bag has 15 hats. Miggy accidentally tore off 5 hats. During the party, only 25 hats were used. How many hats were unused?
Step-by-step reasoning process: There are a total of 15 x 3 = 45 hats in 3 bags. Since 5 tore off, only 45 - 5 = 40 hats were left. Thus, 40 - 25 = 15 hats were unused.