They are: 18+24+30 = 72
Count by 2's.2, 4, 6, 8, 10, 12
The First common multiple of 6 and 7 is 42 and the next common multiple is 84.
The lowest common multiple of 6 and 8 is 24, because there's 4x 6's in 24, and 3x 8's in it too.
The first multiples of 6 are 6,12,18,24,30,36,42,48,54,60,66,72,78,84,90,96 and 102. Is that enough?
6 and 12 are the first two
24.
30
6, 12, 18, 24, 30.
6, 12 and 18.
36
No, 3 isn't a multiple of 6 because the first multiple of 6 is 6. 3 is a factor of 6. 6 is a multiple of 3.