The numbers are: 1 and 20
84
First it adds by 3. Then on 4, 8, 12 it adds by 4. On 5 and 10 it adds by 5. So i guess it is 3, 4, 5.
5 and 6.
-53
5, 10, and 20 are all multiples of 5 and factors of 20.
The first four multiples of five: 5, 10, 15, 20
Yes.
-15
The first 5 multiples of 4 and 20 are 20, 40, 60, 80, 100
The first 5 multiples of 5 are: 5, 10, 15, 20 and 25.5, 10, 15, 20, 25
Multiples. The numbers 10, 15 and 20 are multiples of 5.