B is one of them, i'm not sure how any of the other answers are equivalent to 20% of 45 which is 8.
Need approx 3 oz chemical to 1 gal water.
Conversion factor is then approx. 3 oz
---------
1 gal
Mult this result by 6 gal. This gives you 18 oz, approx.
Now let's look for a more exact solution:
2.75 oz 19 gal
---------- * ---------- = 17.4 oz. The 18 oz estimate was close.
1 gal 3
It would be smaller because 11/12 = 22/24
