$$Super C$$ at Atwater operates between $9$ A$.$M$.$ to $10$ P$.$M each day and it open seven days a week. Currently,

Super C operates six checkout counters each serving its own waiting line. Customers are arriving at the store at

an average rate of $90$ per hour, following Poisson distribution. The service time at each checkout counter is

exponentially distributed with a mean service time of $2$ minutes per customer. Each customer spends an

average of $125$$$.$ Super C has a contribution margin of $15\%$ on all its items.

Super C$$s customer research has established that it incurs Super C a cost of $30$$ per hour that a customer

spends waiting in the system. Super C is employing workers at checkout counters at an hourly wage of $20$$ per

counter. The manger of Super c feels that it might be advantageous to form a simple waiting line serviced by

all checkout counters instead of separate waiting lines.

Suppose:

$$ Current system $=$ separate waiting line for each cash counter, and customers are split into each cash

counter equally $($that is$,$ the arrival rate of each counter is $15$ per hour$),$ and customers are not allowed

to change lines