Assignment:
A small barber shop has a single chair and an area for waiting, where only one person can be in thee chair at a time, and no one leaves without getting their hair cut. So the system is roughly:
Entrance → Wait → Haircut → Exit
Assume customers arrive at the rate of 8 per hour and stay an average of 0.4 hour. What is the Walt Haircut Exit average number of customers in the barber shop?