Consider a single channel, single phase waiting line with Poisson arrivals from an infinite population. The service rates follow exponential distribution. The customers arrive at the rate sf four per hour and service can be performed at an average rate of one every $10$ minutes. Find Utilization of the queuing system b$.$ The average number of customers waiting in the line $.$ A$.$ The average time a customer has to wait before it is attended by the server B d$.$ The total time it takes for the customer to go through the system C c$.$ The probability that exactly $2$ customers will be there in the system