Multiple choice

Two solutions of 80% and 87% purity are mixed resulting in 35 liters of mixture of 84% purity. How much is the quantity of the first solution in the resulting mixture?

  1. 15 liters

  2. 12 liters

  3. 9 liters

  4. 6 liters

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A Correct answer
AI explanation

Using the rule of alligation on the percentage purities, the ratio of the first solution to the second solution is (87 minus 84) : (84 minus 80), which is 3 : 4. Since the total mixture is 35 liters, one part equals 35 divided by 7, giving 5 liters. The quantity of the first solution is 3 parts, which is 15 liters.