Question

In the lab, Elsa has two solutions that contain alcohol and is mixing them with each other. She uses 4 times as much Solution A as Solution B. Solution A is 13%alcohol and Solution B is 16% alcohol. How many milliliters of Solution B does she use, if the resulting mixture has 544 milliliters of pure alcohol?

Answer 1

Solution A: 13% alcohol

Solution B: 16% alcohol

She uses 4 times as much solution A as solution B, so if she used A milliliters of solution A and B milliliters of solution B:

A = 4B ...(1)

Then, the amount of alcohol is:

13% of A = 0.13A

16% of B = 0.16B

The resulting mixture has 544 mL, then:

0.13A + 0.16B = 544

Using (1):

0.13(4B) + 0.16B = 544

0.52B + 0.16B = 544

0.68B = 544

B = 800 mL

Elsa used 800 mL of solution B