35 juice cups and each juice cup holds 12 fluid ounces.

how many gallons is that?

Your answer for this question will be 4 gallons

You have to look it up, but there are are 128 fluid oz in one gallon.

Then find the amount of juice you have total (in fl oz) in the 35 cups

35 * 12 fl oz = 420 fl oz

Then divide by the number of fl oz in one gallon to find the number of gallons

420 fl oz / 128 fl oz = 3.28 gallons