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Given information
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20 feet cost $36
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Find the cost of 1 foot by dividing by 20
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20 feet = $36
1 foot = $36 ÷ 20
1 foot = $1.8
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Find the cost of 15 feet by multiplying by 15
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1 foot = $1.80
15 feet = $1.80 x 15
15 feet = $27
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Answer: $27
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