Least Common Multiple of 8, 12 and 18 by Listing Multiples

Multiples of 8: 8, 16, 24, 32, 40, 48, 56, 64, 72, 80, 88, …
Multiples of 12: 12, 24, 36, 48, 60, 72, 84, 96, …
Multiples of 18: 18, 36, 54, 72, …
LCM(8, 12, 18) = 72