29. A post office has two counters, the first one handles moneY-orders and registration letters, while the second handles all other business. It has been found that service time distributions for both the counters are exponential with a mean service time of 4 minutes per customer. The customers are found to arrive at the first counter in a Poisson fashion with mean arrival rate of 10 per hour while the customers arrive at the second counter in a Poisson fashion with mean arrival rate of 12 per hour. What would be the effect on the average waiting time for the two types of customers if each counter can handle all types of business?