Answer:
Sparkling water: 50 quarts
Grape Juice: 25 quarts
Explanation:
The punch recipe uses 1 1/2 quarts of water and 3/4 quarts of grape juice
That would make a total of
1 1/2 + 3/4 = 3/2 + 3/4 = 6/4 + 3/4 = 9/4 quarts of punch
Therefore to make 75 quarts, we have to figure out how many of 9/4 quarts would be needed.
This is 75 ÷9/4
Dividing by 9/4 is same as multiplying by 4/9
75 ÷9/4 = 75 x 4/9 = 300/9 = 100/3
So we will need 100/3 times as much of both ingredients
For sparkling water this would be
1 1/2 x 100/3 = 3/2 x 100/3 = 300/6 = 50 quarts
For grape juice we will need
3/4 x 100/3 = 300/12 = 25 quarts
(Or we can subtract 50 from 75 to get 25 quarts)