Question: 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? Think carefully first, then make a decision:
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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. So the answer is 6.
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