Noah mixes 3 cups of apple juice with 2 cups of sparkling water to make fizzy juice. To make fizzy juice that taste the same, how many cups of apple juice should Noah use if he uses 5 cups of sparkling water?

Well he needs 3 cups of apple juice to and 2 cups of sparkling water.

So

3 + 2 (Sparkling water would be decreased by 2)

3 + 2 (Sparkling water would be decreased by 2)

3 + 1 Half of a cup of fizzy juice.

So Noah will need 6 cups of apple juice