Before going to Europe on business，a man drives his Rolls-Royce to a downtown New York City bank and asks for an immediate loan of $5，000．The loan officer，taken aback，requests collateral．“Well then，here are the keys to my Rolls-Royce，”the man says．The loan officer promptly has the car driven into the bank’s underground parking for safe keeping，and gives the man the $5，000．Two weeks later，the man walks through the bank’s doors and asks to settle up his loan and get his car back．“That will be $5，000 in principal，and $15.40 in interest，”the loan officer says．The man writes out a check and starts to walk away．“Wait，sir，”the loan officer says．“You are a millionaire．Why in the world would you need to borrow $5，000？”The man smiles，“Where else could I find a safer place to park my Rolls-Royce in Manhattan for two weeks and pay only $15.40？”