math homework for college

Question

For a chemistry experiment, Agatha needs 50 milliliters of 20% acetic acid solution. The laboratory only has 10% and 50% acetic acid solutions. Agatha plans to make the 20% acetic acid solution by mixing together appropriate amounts of the two solutions. Determine the amounts of 10% and 50% acetic acid solution that should be mixed to make 50 milliliters of 20% acetic acid solution.

Answer 1

10X + 50(50-X) = 20(50) = 1000 = 50 ml of 20% solution

10X-50X = 1000-2500

40X = 1500

X = 37 1/2 ml of 10%

50-37.5 = 12.5 ml of 50%

10 is closer to 20 than 50

It's 3 times closer

you need 3 times as much 10% as 50%

3 times 12.5 = 37.5

.10(37.5) + .50(12.5) = .20(50)

3.75 + 6.25 = 10