One solution contains 20% acid and a second solution contains 50% acid. How many ounces of each solution should be mixed in order to have 60 ounces of a 30% acid solution?

Answer 1

amount of 20% solution to be used: x ounce
amound of 50% solution to be used : 60-x

.2x + .5(60-x) = .3(60)
time 10
2x + 5(60-x) = 3(60)
2x + 300 - 5x = 180
-3x = -120
x = 40

40 ounce of the 20% and 20 ounces of the 50% solution should be mixed.