so first we convert to a common number(cups are the smallest so we'll convert to that)
2cups=1pint
2pints=1quart
4quarts=1gallon
1gallon=8pints
1gallon=16cups
1quart=4cups
first week they drank 2 gallons or 2 times 16 cups or 32 cups, 1 quart which is 4 and 1 cup so 32+4+1=37 cups the first week
week two 3 gallons which is 16 times 3 which is 48 cups in second week
second week-first week =difference
48-37=11
11 cups difference
