The breakeven of a certain event is when the amount of cost is equal to the amount gained from the sales. The total cost of producing x car parts is equal to the sum of the fixed cost ($3,000) and the variable cost ($15 per part). This cost should be equal to the revenue when selling the parts for $25 each.
3,000 + 15x = 25x
The value of x from the equation is 300.
Thus, the company should sell a minimum of 300 car parts in order to breakeven.