Question 597441
6*.2=1.2 total gal of acid.
Let x=gal of pure acid required.
x*1.00=x total gal of acid
(6+x)*0.9=.9(6+x) total gal acid
.
1.2+x=.9(6+x)
1.2+x=5.4+.9x
.1x=4.2
x=42 gallons
.
Ed