Question

two solutions of salt water contain 0.1% and 0.22% salt respectively. A lab technician wants to make 1 liter of solution which contains 0.19% salt. How much of each solution should she use?

Answer 1

0.25 L at 0.1% and 0.75 L at 0.22%

Explanation:

We have to:

percent quantity

Salt solution # 1 0.1 x L

Salt solution # 2 0.22 (1 - x) L

Mixture 0.19% 1

We are left with the following equation:

0.1 * x + 0.22 * (1-x) = 0.19 * 1

solving:

0.1 * x + 0.22-0.22 * x = 0.19

0.1 * x- 0.22 * x = 0.19 - 0.22

-0.12 * x = -0.03

x = -0.03 / -0.12

x = 0.25

Which means

Salt solution # 1 0.1% 0.25 L should be used and for salt solution # 2 0.22% 0-75 (1 - 0.25) L