1. A customer arrival monitoring system in a bank branch is registering an inter-arrival time of customers to the bank branch at an average 15 minutes distributed exponentially around the average. The tellers service customers with an average rate of 10 customers per hour following a Poisson process. 4 tellers are serving customers and the total seating capacity of the branch is 25 seats. Find the arrival rate of customers to the bank (per hour) and the average service time per customer.

Then give the Kendall's notation for such a system.