Same Case as Above: Will Rogers owns and manages a taco and soft$-$drink stand in Lubbock near Texas Tech University. On Saturdays, his busiest day, he can service $30$ customers per hour on the average but he only gets $20$ customers per hour on average. Because Will can wait on $50\%$ more customers than actually visits his restaurant, it does not make sense to him that he should have any waiting lines. After looking at the problem you find that it follows the six conditions for a single$-$server waiting line.

What is the average waiting time in the system?

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

a

$2$ minutes

b

$3$ minutes

c

$4$ minutes

d

$5$ minutes

e

$6$ minutes