A)

A and C mall is a busy centre for residents in East Legon and its sourrounding community. Assume that 2 customers arrive every 12 minutes and 3 customers are served every 15 minutes and that currently, there is only one cashier.

a) Determine the average waiting time in minutes before service begins.

b) Advice the management the proportion of the time that a customer has to wait.

c) Management perceives that the waiting time computed in (ii) above is not acceptable and is faced with two options.

Management can either employ an assistant for the cashier or open a second cash machine.

The former, if implemented, will enable 4 requests to be served every 15 minutes and the assistant will receive a monthly salary of GH160. The latter, if implemented will improve the arrival rate to 1 customer every 12 minutes.

However, it requires an initial capital outlay of GH3000 and the cashier who will operate the cash machine will receive a monthly salary of GH250. The shop avoids a loss in sales of GH80 per month for each minutes that average customer waiting time is reduced.

Calculate the financial gain to A and C mall under option 1 and advice management on the option.

d) Calculate the financial gain to A and C mall under option 2, assuming the initial capital outlay is sunk cost and advice management on this option.