Question 728460
    how many liters of a 30% saline solution must be mixed with a 40% saline solution to obtain 25 liters of a 32% saline solution?
.
Let x = amount (liters) of 30%
then
25-x = amount (liters) of 40%
.
.30x + .40(25-x) = .32(25)
.30x + 10-.40x = 8
10-.10x = 8
-.10x = -2
x = 20 liters (of 30%)
.
amount of 40%:
25-x = 25-20 = 5 liters