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How many millimeters of solution B does she use, if the resulting mixture is a 5% alcohol solution

How many millimeters of solution B does she use, if the resulting mixture is a 5% alcohol-example-1
User Kiyah
by
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1 Answer

13 votes
13 votes

Let a represent the volume of solution A. If it contains 2% of alcohol, then the amount of alcohol that A contains is 2/100 * a = 0.02a

If A = 200, then the amount of alcohol in A is 0.02 * 200 = 4

Let b represent the volume of solution B. If it contains 7% of alcohol, then the amount of alcohol that B contains is 7/100 * a = 0.07b

The total volume of solution A and B is (a + b)

If the volume of A = 200, then the total volume or resulting mixture is 200 + b

If the mixture contains 5% alcohol, the the amount of alcohol in the mixture is

5/100 * (200 + b)

0.05(200 + b)

By equating the concentrations, we have

4 + 0.07b = 0.05(200 + b)

4 + 0.07b = 10 + 0.05b

0.07b - 0.05b = 10 - 4

0.02b = 6

b = 6/0.02

b = 300

She needs to use 300 milliliters of solution B

User Coreuter
by
3.0k points
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