For questions $7$ and $8$

Imagine that you are an manager of a business with the following characteristics: Customers arrive at a rate of $15$ per hour and the service rate is $30$ customers per hour. There is only one server. Interarrival times and service times are exponential.

Question $7$

How many customers $($on average$)$ are waiting in line to be served?

$0\mathrm{.}3125$

$0\mathrm{.}5$

$1$

$0\mathrm{.}75$

Question $8$

$2$ pts

What is the average waiting time $($in min $)$ in the system of customers?

$3\mathrm{.}25$

$3$