Arithmetic and Algebra Session 17 Mixture problem

GRE Quant Problem Solving
1

Gregmat Doubt
Gregmat Doubt1920×1128 59.2 KB

Hello!
Greg’s thought process for this question was edited out. So, I don’t understand how he got 7.2 as the answer.
My answer to this question was 18 grams.

  1. Initial mixture had 40% vinegar, which is 12 grams.
  2. This means, we have 18 grams of oil in this mixture.
  3. The problem asks us about how many more grams of oil we should add to this mixture to make the vinegar 25%.
  4. To make the 12 grams of vinegar- 25% of the mixture, we need 36 grams of oil, of which 18 is already in the mixture.
  5. So the answer is 18 grams.
  6. New mixture ratio of vinegar : oil is 12:36

Could anybody confirm if my thought process and answer is correct? If not, could you help me out?

2

Try your answer out first.

That isn’t correct. You have a 12 g mixture of vinegar and oil - 40% or 4.8 g of this mixture is vinegar. Hence (12 - 4.8 = 7.2) g - the rest - is oil.

3

The way I comprehended the question was wrong :smiling_face_with_tear:
Got it! Thank you so much.

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