Answer:
5 people= $100, 10 people = $200, 15 people= $300, 20 people=$400
Explanation:
For five people your gonna do 5x20 which equals 100
For ten people you do 10x20 which is 200
For fifteen people you do 15x20= 300
And finally you need to do 20x20= 400
I hope this helps, have a good day <3