At the same time, a local train traveling 30 miles an hour and carrying 40 passengers leaves Phoenix bound for Santa Fe. It's eight cars long and always carries the same number of passengers in each car. An hour later, a number of passengers equal to half the number of minutes past the hour get off, but three times as many plus six get on. At the second stop, half the passengers plus two get off, but twice as many get on as got on at the first stop.
