Math word problem

Question

an auto repair shop charges a customer $570 to repair a car. The bill listed $70 for the parts and the remainder for labor. if the cost of the labor is $50 per hour, how many hours of labor did it take to repair the car?

Answer 1

The bill consists of the parts plus the labor and the labor is the hourly rate times the number of hours. So

570=70+50h

 

so subtract 70 from both sides

 

500=50h

so h= 10 hours.