A self$-$service restaurant processes on average $1500$ customers per day. On average, there are $50$

customers waiting to place an order, waiting for an order to arrive or eating. Out of the $50$

customers, $40$ customers on the average are eating. What is the average wait time at the counter?

Assume that the restaurant operates $15$ hours per day.

A$)30$ minutes

B$)6$ minutes

C$)0\mathrm{.}4$ minutes

D$)2$ minutes

E$)24$ minutes