Question

How many liters of a 35% salt solution must be mixed with 20 liters of 70% salt solution to obtain a solution that is 45% salt? What is the equation?

Answer 1

.35 x + .70 (20) = .45(x+20)

50=x

Explanation:

Let x = liters of 35% salt solution

We have 20 liters of 70%

We have a total of 20+x liters of 45%

.35 x + .70 (20) = .45(x+20)

Distribute

.35x + 14 = .45x +9

Subtract .35x from each side

14 = .10x +9

Subtract 9 from each side

5 = .10x

Divide each side by .1

5/.1 = x

50=x