Answer:
6
Explanation:
To find the hours of labor it took to repair the car, we need to subtract the cost of parts from the total cost and then divide the result by the cost per hour of labor.
So, $340 - $100 = $240 was spent on labor.
$240 ÷ $40 per hour = 6 hours of labor.
Therefore, the answer is OB. 6 hours.