A certain quantity of 40% concentration solution is replaced with 25% concentration solution such that the concentration of the combined amount is 35%.
What's the ratio of the amount of solution that was replaced to the amount of solution that was not replaced?	Choose the correct option:
A) 1:3  B) 1:2  C) 2:3  D) 2:1  E) 3:1
From the wording in the prompt, we're essentially mixing two liquids:   Liquid X is 40% concentrate   Liquid Y is 25% concentrate   We're supposed to mix some of each and end up with a solution that is 35% concentrate. The prompt doesn't give us specific amounts of liquids to work with and the question itself asks for the ratio of the two liquids, so we could even TEST VALUES if doing it that way made it easier for you. For now though, here's the Algebra:   X = # of ounces of liquid X   Y = # of ounces of liquid Y   (.4X + .25Y) / (X + Y) = .35   .4X + .25Y = .35X + .35Y   .05X = .1Y   5X = 10Y   From here, you have to be CAREFUL to answer the question that is ASKED.   5X = 10Y   Y/X = 5/10 = 1/2   ANSWER:1:2
<result>B</result>
A certain quantity of 40% concentration solution is replaced with 25% concentration solution such that the concentration of the combined amount is 35%.
What's the ratio of the amount of solution that was replaced to the amount of solution that was not replaced?