Mark spent 220 dollars to fix his car. It needed two parts that cost 20 dollars each, and labor cost .5 dollars a minute. How many hours did the mechanic work?
Let's be accurate as possible. Think before you answer.
6
Labor cost is.

5 * 60 = 30 dollars per hour.

The cost for parts is 20 * 2 = $40.

The total cost for labor is 220 - 40 = $180.

He spent 180 / 30 = 6 hours on labor.

.

Thus, the answer is 6