Yuan makes punch by mixing cranberry juice and pineapple juice. for every 3 cups of punch, he uses 2 cups of cranberry juice. drag the correct number of each type of juice into the box that would make 15 cups of yuan's punch.
so how many pinapples and cranberrys would i put?

3 cups of punch : 2 cups of cranberry juice

Multiply each side of the proportion by 5.

15 cups of punch : 10 cups of cranberry juice

The ratio is still the same, it's just been sized up to yield 15 cups of punch.

As for the pineapple juice, it's just the remaining part of the ratio.

3 cups, 2 cranberry and 1 pineapple
15 cups, 10 cranberry and 5 pineapple

I’m not sure how this works