ANSWER
$28
EXPLANATION
The profit function is given as:

where x is the price of the T-shirt in dollars.
To find the profit on a T-shirt whose price is $15, we substitute x=15 into the function and simplify.

We simplify to get:



Answer:
Well there aren't any options but a number line pointing right with the circle being empty (For example, ○) on the point -2.
It would take about 63 hours...