Question 35037
Let the answer be x
Then .12x + .30(60-x)= .18(60)
=> 12x + 30(60-x) = 18(60)
=> -18x = -720
=> x=40
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40 ounces of 12% alcohol is needed to mix with 20 ounces of 30% alocohol to prepare 60 ounces of 18% alocohol.