The toll booth operator cannot take a break as long as there are cars in her queue. The times between arrivals of cars are independent with mean 5 minutes. It takes her on average 2 minutes to process each customer. These service times are independent for different customers and independent of the arrival times of the cars. Let pn be the probability that the toll booth operator has had to serve n customers in a row without a break. Show that pn 0 as n