PROBLEM 2 People arrive randomly at a bank teller at an average rate of 90 an hour. The teller takes an average of 0.5 minutes to serve each customer and incurs total waiting costs of BD 30 an hour. Given that; La = 12 / (-1) Wq = 1/(-A) Ls = La + /V Ws = Ls + A/N cost = Wax A x cost Compute the bank's service rate per hour. Select one: O a. 30 O b. 150 C. 120 Clear my choice