Question

A chemist has one solution that is 25% salt and 75% water and another solution that is only 5% salt. How many milliliters of each should the chemist use to make 1400 ml of a solution that is 10% salt.

Answer 1

10% of 1400 milliliters is 140 milliliters, so 140 milliliters is Salt

Answer 2

Let x= number if mL of the first solution. 1400-x= number of mL of second solution.
Equation: (1/4)x + (1/20)(1400-x) = 140
(1/4)x + 70 - (1/20)x = 140
(4/20)x =70
(1/5)x = 70
x = 350
350 mL of first
1050 mL of second