Question 669862: How many gallons of a 50% acid solution must be mixed with 40 gallons of a 19% solution to obtain a solution that is 40% acid? Answer by mananth(16946) (Show Source):
You can put this solution on YOUR website! -------------- percent ---------------- Amount
Acid solution I 19 ---------------- 40 gallons
Acid solution II 50 ---------------- x gallons
Mixture 40 ---------------- 40 + x gallons
19*40+50x=40(40 +x)
760+50 x = 1600 + 40 x
50x-40 x=-760+ 1600
10 x = 840
/ 10
x = 84 gallons Acid solution II