Step-by-step explanation:
Priya's mix follows the mix ratio of 3/5 (scoops of powder to cups of water).
every mix that tastes exactly the same has to have the same ratio.
so, the possible number combinations are
3/5 × x/x, x = 1, 2, 3, 4, 5, 6, ...
3 scoops to 5 cups
6 scoops to 10 cups
9 scoops to 15 cups
12 scoops to 20 cups
15 scoops to 25 cups
...