A woman went into a bank in London wishing to loan $3,000 for one month. The loan officer said that he would require collateral. The woman says, βI have a Ferrari; here are a set of keys. Keep it until I repay the loan.β The loan is authorized and the Ferrari driven away for safe keeping. The woman returns one month later, pays the $3,000 loan together with $20 interest and the car is returned to her. Clearly puzzled, the loan officer says to her, βWith respect, madam, I don't understand why somβ¦