20 has six factors.
1,2,4,5,10,20
Four common factors.
85 has four factors.
Four, four, six, three, six and two factors respectively.
15, 20, 30, 60
It is 10 whose factors are: 1, 2, 5 and 10
The factors of 20 are 1,2,4,5,10 and 20. Two are odd, four are even.
The two factors of 24 that give you a sum of 20 are 12 and 8.
The other factors could be 4 and 5 or 1 and 20.
Four of them.
5, 10, and 20 are factors of 20 that are not also factors of 12.