how many liters of a 5% solution of salt should be added to a 25% solution in order to obtain 1120 liters of a 22% solution

Answer 1

volume of the 5% solution needed is x L
volume of the 25% solution needed is 1120 - x L

.05x + .25(1120-x) = .22(1120)
times 100
5x + 25(1120-x) = 22(1120)
5x + 28000 - 25x = 24640
-20x = -3360
x = 168

They need 168 L of the 5% solution and 952 L of the stronger stuff