No.
1
The Least Common Multiple (LCM) for 20 33 is 660.
1, 2, 4, 5, 10, 20
4, 8, 12, 16, 20
No, also 1, 4, 5, 20
6, 12, 18
20 and 14 are both integers. The common denominator of 20/1 and 14/1 is 1. The least common multiple is 140.
Factor of 24, but not a multiple of 8
1 and 5
Since 10 is a factor of 20, all multiples of 20 are multiples of 10. This is also true of 1, 2, 4 and 5.
1, 2, 4
1 and 5