Good Riddles

Question: someone came into my shop and stole 100 dollars from the register without my knowledge. the person came back 5 minutes later with the same 100 dollars and bought 70 dollars in items and i gave him back 30 dollars change. How much did i lose?

Question: I move faster in certain solids, but slower in certain gases. I am typically broken by objects with large masses. I can be used as for pleasure, practice, and even an alarm. If used excessively, I can cause harm. What am I?

Question: Give me food, and I will live. Give me water, and I will die. What am I?

Question: What jumps when it walks and sits when it stands?

Question: A surgeon named Hal and a bus driver named Al are both in love with the same woman named Paige. Al needs to go for a long trip of 10 days. Before he left he gave Paige 10 apples. Why?