Question 978107
The total cost is $65,000 fixed + 15,000*$7.5=$65,000+$112,500=$177,500

Total revenue is 15000 tires * $25/tire=$375,000

Profit is Revenue-Cost=$375,000-$177,500=$197,500

Break even is:
$65,000+$7.5x=$25x, where x is the number of tires.   It is the function for cost=function for profit.
$65,000=$17.5 x
x=3715 tires (3714 is close but a slight loss)