5 and 6 have.
3 and 10 have.
2 and 15 have.
1 and 30 have.
30 and 60 have an LCM of 60.
You need at least two numbers to find an LCM. If that's 5 and 30, the LCM is 30.
30 and 60
20 and 30
3 and 30
3 and 30
3 and 30
3 and 30
In order to have an LCM, there has to be two or more numbers. Some multiples of 30 are 60, 90, 120, etc.
5 and 6 have an LCM of 30. So do 10 and 3.
Since 30 is a factor of 90, the LCM is the larger of the two numbers, ie 90.
You need at least two numbers to find an LCM. If that's 21 and 30, the LCM is 210.