Exercise 7.3.1 You have been asked to consider three systems for providing service when custo mers arrive with a mean arrival-rate of 24 per hour (a) a single channel with a mean service-rate of 30 per hour at 5 per customer and fixed costs of t50 per hour; (b) 2 channels in parallel each with a mean service rate of 15 per hour at 4 per customer, and fixed costs of 30 per hour per channel (c) 3 channels in parallel with a mean service-rate of 10 per hour at 3 per custo- mer, and fixed costs of 25 per hour per channel. Your tests have confirmed that the system is identical in all other aspects with a simple queue You are required to calculate (a) the average time a customer is in the system when 1, 2 and 3 channels are in use (b) the most economical system to adopt if the value to the firm of customers time is ignored, and to state the total cost per hour of this system (c) the implied value to the firm of customers' time if the firm is indifferent between the 2- and 3-channel systems. (ICMA Prof )