Same case as above: Consider a single$-$line, single$-$server waiting line system. Suppose that customers arrive according to a Poisson distribution at an average rate of $60$ per hour, and the average $($exponentially distributed$)$ service time is $45$ seconds per customer.

What is the average amount of time a customer sfyends in the system?

Select an answer and submit. For keyboard navigation, use the up$/$down arrow keys to select an answer.

a $1$ minute

b $2$ minutes

c $3$ minutes

$4$ minutes

$5$ minutes