The length of time, y , that a customer spends in line at a bank teller’s window before being served is described by the exponential pdf fy (y) = 0.2e−0.2y , y ≥ 0.
(a) what is the probability that a customer will wait more than ten minutes?
(b) suppose the customer will leave if the wait is more than ten minutes. assume that the customer goes to the bank twice next month. let the random variable x be the number of times the customer leaves without being served. calculate px (1).