3.Two workers control 10 machines. The adjustment time is distributed exponentially and has an average time of 14 minutes per machine. Machines need adjustments after working for an average of 86 minutes. The machines produce 50 products per hour at work. Find the following:

(a) the probability that the machine will have to wait for adjustment

(b) Average number of machines waiting for adjustment

(c) Average number of machines in service

(d) If the cost of each machine considering the adjustment time is \70,000 per hour and the cost of the operator is \15,000 per hour, what is the optimal number of workers?