Latoya used 4 gallons of ginger ale 1 gallon of orange juice and 1gallon of pineapple juice to make punch for her brothers birthday party . how many cups of punch will latoya have for her brothers birthday party

A cup is 250 mL. 
1 gallon in the US is 3.78 L * 1000 mL / 1 L = 3780 mL
1 gallon contains 3780 / 250 = 15.12 cups.

So the number of gallons for the punch = 4 + 1 + 1 = 6 gallons.

1 gallon gives 15.12 cups
6 gallons will give x

1/6 = 15,12/x
x = 6 * 15.12
x = 90.72 cups. That's for an awfully big party.