Please just answer C-D with formulas and explanations

3. MusicVenue is a concert organizer that is evaluating the installation of portable toilets in the arena where a concert is going to take place. In particular, they are considering giving service to a part of the complex that is far away from the existing restrooms. Assume there will be one single queue to access all portable toilets in this area and that only one person uses a toilet at a time. There are 2.5 arrivals per minute on average, with a coefficient of variation of.5, and the average time a person spends in the toilet is 3 minutes (with coefficient of variation of 1). Suppose MusicVenue decides to install 12 portable toilets. a a. What is the average utilization of the 12 toilets? b. What is the expected time a customer will have to wait? c. How long will the average toilet be empty during a 4-hour concert? d. What is going to be the average number of people in the queue? (Your answer does NOT have to be an integer.) e. The firm does not want the average waiting time to be higher than 2 minutes. What is the minimum number of portable toilets that the firm will have to install to meet that goal? (Your answer should be an integer they can install 2 toilets or 3 toilets but they cannot install 2.6 toilets)