Hans is in dire need of extra cash for a facelift and goes to his friend Greta for help. When approached, Greta offers to lend Hans the money he needs. The two of them enter into the following agreement: "Greta promises to lend Hans $20,000 (twenty thousand dollars) if, in exchange, Hans agrees to pay Greta $10 dollars if and when he thinks he can afford it." Hans tells Greta that he will be calling the plastic surgeon, Dr. Tuck, that very day to schedule the operation, and Greta says she will pay for the facelift from Dr. Tuck, once Hans gets his facelift and gives her the bill. The next day, Hans goes to the surgeon and has the facelift performed. When Hans presents the bill from Dr. Tuck and asks Greta for the money to pay the surgeon, Greta refuses to give him the money because she thinks Hans looks hideous, and doesn't want to be his friend anymore. Hans is extremely upset because he now owes Dr. Tuck $20,000 for the facelift operation, and the surgeon is suing Hans. How is a court likely to resolve this dispute? Be sure to include all theories of contract law