Question 1010704
Call the amount of 25% salt solution used, x.
Then the amount of 10% salt solution must be 120-x.
The set up looks like this
.25x + .10(120-x) = (.15)(120)
.25x + 12 - .10x = 18
.15x = 6
x = 40 liters of 25%
120-x = 80 liters of 10%