what are the rules?

Answer:
See below
Step-by-step explanation:
3rd row 420 | 21
4th row 20 | 1
5th row 100 | 5
6th row 1000 | 50
7th row 350 | 17.5
constant is 20
3rd row 420 | 21
4th row 20 | 1
5th row 100 | 5
6th row 1000 | 50
7th row 350 | 17.5
constant is 20