Give the step-by-step reasoning process and then the final answer. Gary is buying chlorine for his rectangular pool, which is 10 feet long, 8 feet wide, and 6 feet deep. Gary needs to buy one quart of chlorine for every 120 cubic feet of water in his pool. If chlorine costs $3 a quart, how much does Gary spend on chlorine?
First find the volume of the pool by multiplying the length by the width by the height: 10 ft * 8 ft * 6 ft = 480 cubic feet. Then divide the volume of the pool by the number of cubic feet one quart of chlorine can sterilize: 480 cubic feet / 120 cubic feet / quart = 4 quarts. Then multiply the number of quarts Gary needs to buy by the price per quart to find out how much money he spends: $3 / quart * 4 quarts = $12.
The final answer: 12.