SOLUTION: Hi a chemical solution was made by mixing acid with water in the ratio of 1:4.the solution was then mixed with water in the ratio of 1:3.if 120ml of water was added to make the

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Question 1030957: Hi
a chemical solution was made by mixing acid with water in the ratio of 1:4.the solution was then mixed with water in the ratio of 1:3.if 120ml of water was added to make the final solution how much acid was used.
thank you
Answer by KMST(5328) About Me  (Show Source):
You can put this solution on YOUR website!
THE FIFTH GRADER SOLUTION:
To make the final solution, 3 parts of water were added to 1 part of the first mixture.
If those 3 parts were 120 mL of water, then 1 part was 120mL%2F3=40mL .
The first mixture had 1 part of acid in 5 parts of total mixture (1 part + 4 parts of the 1:4 mixture).
If those 5 parts were 40 mL, then the original 1 part of acid was
40mL%2F5=highlight%288mL%29 .

MAKING IT LOOK LIKE ALGEBRA:
x= volume of acid used, in mL.
4x= volume of water (in mL) mixed with x mL of acid.
x%2B4x=5x= volume of 1:4 acid:water mixture, in mL.
5x%2F120=1%2F3= ratio of volumes of first mixture to water added to make the final solution.
5x%2F120=1%2F3 --> %285x%293=1%2A120 --> 15x=120 --> x=120%2F15 --> highlight%28x=8%29