16/4 QUARTS
There is no fraction. At best, you could write it, in ratio form, as 1/1 gallon. But that does not make it a fraction!
1 (US) Gallon=3.78541 Litres
-- As a fraction of a pound . . . . . 1/4 -- Fraction of a cup . . . . . 1/2 -- Fraction of a pint . . . . . 1/4 -- Fraction of a quart . . . . . 1/8 -- Fraction of an ounce . . . . . 4/1 -- Fraction of a gallon . . . . . 1/32
There is not enough information. If you want a fraction, there needs to be another thing to compare it with e.g. what fraction of a gallon is a pint? 1/8 what fraction of a gallon is a quart? 1/4 But you can't say what faction is a gallon without stating what you are comparing it with.
1/2 a gallon