THE NUMBER OF CUSTOMERS ARRIVING AT A RAILWAY RESERVATION COUNTER...

19. The number of customers arriving at a railway reservation counter is Poisson

distributed with an arrival rate of eight customers per hour. The reservation clerk

at this counter takes six minutes per customer on an average with an

exponentially distributed service time. The average number of the customers in

the queue will be

(A) 3

(B) 3.2

(C) 4

(D) 4.2