The time between arrivals of customers at a bank during the noon-to-1 p.m. hour has a uniform distribution between 0 to 120 seconds. What is the probability that the time between the arrival of two customers will be
a. less than 20 seconds?
b. between 10 and 30 seconds?
c. more than 35 seconds?
d. What are the mean and standard deviation of the time between arrivals?
