MC Qu$.13-56$ Customers filter into a record shop at an$...$

Customers filter into a record shop at an average of $1$ per minute $($exponential interarrivals$)$ where the service rate is $15$ per hour $($exponential service times$).$

What is the average number of customers in the system with $8$ servers?

Multiple Cholce

$6$

$5$

$4$

$4$

$2$

$$

$3$