I came across the following queuing theory problem in my book and I have no idea how to solve it. It seems similar to the other ones that I've solved but there is information missing, so I assume that it must have another method.
"There is a small fast food restaurant with 1 server. The server could serve, on average, 30 customers per hour, but he chooses to only receive 20 because he doesn't like long lines. The administration is considering hiring an extra server.
What is the utilization rate of the system? Average amount of clients in the system? Average waiting time in the system?
Repeat the calculations, but with 2 servers."
So I don't understand what exactly is it meant by "the server could serve 30 people per hour, but chooses to serve 20". Does this mean that it's a finite queue? Or does it mean that the system is being underutilized?
Is the service rate 20/60?
And also, is "20 customers per hour" the same as the arrival rate? How does having multiple servers changes the outcome?