How many gallons of a 25% acid solution should be added with 10 gallons of a 12% acid solution to obtain a 20% acid solution
+36915 acid in ingredients = acid in final sol'n
x = 25% gallon amount
.25 x + .12 (10) = .20 (10+x)
.05x = .8
x = 16 gal of 25%
