You need at least two numbers to find an LCM.
It is: 21
42, the answer to all questions!
180
50
72
90
It is 6
The Least Common Multiple (LCM) for 32 45 is 1,440
The Least Common Multiple (LCM) for 13 17 is 221.
The Least Common Multiple (LCM) for 20 55 is 220.
The LCM is 16.
252