A recipe calls for 3 potatoes to serve 4 people. If Jack is planning to serve a crowd of 20 people, how many potatoes should he use?

Explanation:

4 times 5 equals 20, so multiply 3 times 5 too and it equals 15.

This is correct

15 potatoes

Explanation:

well if 3 potatoes serve 4 people and 4x5 =20 5x3=15

I hope you get this right :)