need help on these 3 regarding operations management.

Customers join a line in a retail store at the rate of 20/hour. There is only one cashier, with a service rate of 25/hour. (1) The average length of the line of "waiting customers" is = people (round to two places of decimal) (2) The average "waiting time" for a customer before starting the checkout process decimal) minutes (round to TWO places of Suppose the management is thinking of replacing the human cashier by an electronic checkout process that will have exactly same service rate but now it will have a constant service time. So, essentially u remains the same, except it is constant now. (3) The average length of the line of "waiting customers" in this arrangement is = people (round to two places of decimal) (4) The average waiting time for a customer before starting the checkout process = minutes (round to two places of decimal) In a store customers arrive at the checkout area @ 43/hour. Cashiers are trained to check out at the rate of 15/hour. What is the minmum number of cashiers needed to avoid infinitely long line? The minimum number of cashiers needed is cashiers. (an integer response is expected) In the check out area of a store, there are 6 lines of customers each being served by an individual cashier. The cashiers have a service rate of 20 per hour. The arrival rate or, 1, for any of the lines is 17 per hour. Do the following: (enter a numeric value of 1, 2 or 3 after the models described in (1) The model of waiting line management in use is Model your text) (2) The average length of any of the lines of "waiting" customers (Round TWO places of decimal) (3) The average waiting time for any customer is minutes (Round to TWO places of decimal) (4) The probability that an arriving customer will have to wait = (answer in decimal fraction up to THREE places of decimal) (5) The probability that an arriving customer will NOT have to wait = decimal) (answer in decimal fraction up to THREE places of