18, yes.
21, no.
Multiples of 6: 12, 18, 24 Multiples of 7: 14, 21, 28
3, 6, 9, 12, 15, 18, and 21 are.
The multiples of 3 are: 3, 6, 9, 12, 15, 18, 21, etc ...The multiples of 6 are: 6, 12, 18, 24, etc ...The multiples of 18 are: 18, 36, 54, etc ...The lowest multiple common to 3, 6, and 18 is 18, so the LCM = 18.
3, 6, 9, 12, 15, 18, 21.
6, 12, 18. 7, 14, 21.
3, 6, 9, 12, 15, 18, 21 and so on.
3, 6, 9, 12, 15, 18, 21
To find the common multiples of 3, 6, and 18, we need to list out the multiples of each number and find the numbers that appear in all three lists. The multiples of 3 are 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, and so on. The multiples of 6 are 6, 12, 18, 24, 30, and so on. The multiples of 18 are 18, 36, 54, 72, and so on. The first three common multiples of 3, 6, and 18 are 18, 36, and 54.
no they are nor multiples of 6
3: 3, 6, 9, ... 6: 6, 12, 18, ... 18: 18, 36, 54, ... The lcm(3, 6, 18) = 18, so the multiples of 18 are common multiples of all of them.
Factors of 126 are 1, 2, 3, 6, 7, 18, 21, 42, 63, 126 Of those factors, 3, 6, 18, 21, 42, 63, 126 are multiples of 3.
18 and all the multiples of 18.