A gallon is equivalent to 128 fluid ounces. Therefore, in 400 gallons there are
[tex]400\cdot128=51200[/tex]51200 fluid ounces.
Divide that last result by the 16 ounces that make a serving,
[tex]\frac{51200}{16}=3200[/tex]Therefore, the answer is 3200 servings.
