No.
The Least Common Multiple (LCM) for 20 33 is 660.
1
1, 2, 4, 5, 10, 20
No, also 1, 4, 5, 20
4, 8, 12, 16, 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.
1 and 5
Factor of 24, but not a multiple of 8
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 and 5
1, 2, 4