This cannot be answered properly because at least two numbers are required.
The least common multipule of 60 and 72 is 360.
6 (6,12,18,24,30) 9 (9,18,27,36,45) answer:18
8
it is 6
128
252
60
21
1650
The Least Common Multiple (LCM) for7 20is140
36
945