Question

if 1 bottle of gas treatment (5.25 oz/135 ml) treats 21 gallons of gas, how much gas treatment would be used to treat 1 gallon of gas?

Answer 1

Divide the given amounts by 21 to find the amount that would be used for 1 gallon.
135 ÷ 21 = 6.42857142857 ml
5.25 ÷ 21 = 0.25 0z
1 gallon of gas woud need 0.25 oz/ 6.42857142857 ml of gas treatment

Hope this helps (: