Given:
orange juice: 4 cups
pineapple juice: 4 cups
red tropical juice: 8 cups
ginger ale: 10 cups
The total number of cups that would give 1 recipe is:

Next, we convert the number of cups obtained above to quarts:
Recall that:

Hence, to make 1 recipe, Jenna would need:

To make half a recipe, she would need: