Alternative I: Adding extra employee

Adding extra employees will cost the market manager $$100$ per week for each employee added $($since these extra employees will not be cashiers but only packers, so the rate is less$).$ However, each extra employee will increase the service rate by $10$ customers per hour. Note that there will be a single cash counter.

Alternative II: Adding more checkout counters with a single line serving all counters In this case the market can decide to build new checkout counters with each counter being served by a separate cashier $($there will be no helpers$).$ The customer at the top of the waiting line goes to whichever counter is free. While each cashier will cost $$\frac{180}{?}$ week, the amortized cost of building the new counters will be $$\frac{1000}{?}$ year for each new counter added. We assume that the service rate of each new check out channel will be same as the old one.

Taking both the capacity and waiting costs into account which alternative is the best for the market $($assume $52$ weeks$/$year$).$ What will be the average waiting time in the system and in the line for the customers if the market is operating at its optimal configuration? points$)$