capacity

Lisa is walking down the street in January when she notices a young man named Denny.  Denny looks a little worse for wear, so Lisa offers to buy him lunch. As they are talking, Denny says to Lisa: “I’m in a pretty rough spot. I don’t have any money right now. But I promise to pay you $450 if you give me that coat you are carrying and some food (that sum represents the reasonable value of those items).  Lisa responds: “How old are you?” Denny states that he is 20. However, this is a lie. Denny is actually 16.  Lisa looks him over one more time, and she agrees to the exchange.

Before they leave, Denny says,"Actually, I will promise to give you another $50 if you let me borrow your bike."

Lisa writes down all of these promises into a contract. Both parties sign the contract, and they go to the bank and have it notarized.

• A week later Denny trashes the bike, and he tells Lisa that he is not going to pay. Lisa sues Denny in court for breach of contract, and she learns that he is only 16.
• What is likely to happen in the court case?