How many quarters would it be if a gallon milk jug was a fourth full?

A gallon milk jug holds 128 fluid ounces. If it is a fourth full, it contains 32 fluid ounces. Since there are 8 fluid ounces in a cup, this is equivalent to 4 cups. As there are 4 cups in a quart, a fourth full gallon jug would be 1 quart.