Two airplanes are flying in the same direction in adjacent parallel corridors. At time t = 0, the first airplane is 10 km ahead of the second one. Suppose the speed of the first plane (km/hr) is normally distributed with mean 530 and standard deviation 9 and the second plane's speed is also normally distributed with mean and standard deviation 515 and 9, respectively.
A) What is the probability that after 2 hr of flying, the second plane has not caught up to the first plane?