A Professor Is Holding Office Hours for a Class of 15

Essay

A professor is holding office hours for a class of 15 students.Each student arrives on average once per hour.The arrival process follows a Poisson distribution.The time the professor spends with each student follows an exponential distribution with an average of 5 minutes.(Assume that each student may seek help and may decide to make multiple trips to the professor's office. )Answer the questions below.
a.How many students are waiting to see the professor on average?
b.What is the average waiting time in the queue?
c.What is the average wait in the system?