Please solve the ff:

A department store opens at 9 am daily. Suppose customers of the store arrive at a steadily increasing rate that starts with an initial rate of2 customers per hour at 9 am and reaches a rate of 20 customers per hour by 12 noon. Assuming arrivals follow a nonhomogeneous Poisson process, what is the probability that 3 customers will arrive between 10:00 and 10:30 am on a Monday morning