Problem 1 The manager of Hills Bank at Capitol Mall must decide how many cashiers must work on Fridays. For every minute a customer waits in a queue, Hills manager assumes an incurred cost of $5. On a typical Friday, three customers arrive at the bank every minute, on average, and an average cashier's transaction takes 50 seconds. One hour of a cashier's work costs the bank $24.50 (including benefits and everything) How many cashiers should work on Fridays to minimize total cost (service & waiting)? What is that minimum cost per hour? (It is assumed that customers arrive following a Poisson distribution, and that service times follow an exponential distribution)