Question 349990
10% peroxide solution 500 gallons
100%   let it be x gallons
to a 28% solution total = 500 +x gallons
..
0.1*500 +x = 0.28(500+x)
50+x =140+0.28x
x-0.28x=140-50
0.72x=90
/0.72
x=90/0.72
125 gallons