At the start of football season, the ticket office gets very busy the day before the first game. Customers arrive at the rate of three every 10 minutes and the average time to transact business is 3 minutes. a. what us the average number of people in line? b. what is the average time that a person will spend at the ticket office? c. what proportion of time is the server busy? d. what is the average number of people receiving and waiting to receive tickets? e. what is the average time that a person will spend waiting in line at the ticket office?