A lawyer communities daily from his suburban home to his midtown office. the average time to be one~way trip is 24 minutes, with a standard deviation of 3.8 minutes, assume the trip time to be normally distributed.（a) what's the probability that a trip will take at last 1/2 hour?
(b) if the office opens at 9:00 A. M and the lawyer leaves his house at 8:45 A. M. daily what percentage of the time is he late for work?
(c) if he leaves the house at 8:35 A. M. and coffee is served at the office from 8:50 A. M. 9:00 A. M. what's the probability that the misses coffee?