Buses arrive at a specified stop at 15-minute intervals starting at 8.00 A.M. That is, they arrive at 8.00 A.M., 8.15 A 8.30 A.M., and on. If a passenger arrives at the stop at a time that is uniformly distributed between 8 A.M. and 8:30 AM, find the probability that she waits than 5 minutes for a bus.