John's hair grows 1.5 inches every month. Every time it gets to 9 inches long he cuts it down to 6 inches. A haircut costs $45 and he gives a 20% tip. How much does he spend on haircuts a year?
Thoughts? Step-by-step reasoning:
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He cuts off 9 - 6 = 3 inches when he gets a haircut. That means he needs to cut it every 3 / 1.5 = 2 months. So he gets 12 / 2 = 6 haircuts a year. He gives a 45 * .2 = $9 tip. So that means each hair cut cost 45 + 9 = $54. So he pays 54 * 6 = $324 a year.
Thus, the answer is 324.
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