There are infinitely many multiples of 9 and 21 so it is impossible to list them. One of their multiples is 9*21 = 189.
All multiples of their lowest common multiple: lcm(3, 5, 7) = 105 → the numbers less than 400 with 3, 5, 7 as factors are: 105, 210, 315.
There are infinitely many common multiples of 3, 5 and 7, each one 105 larger than the previous one. Or to put it another way: the common multiples of 3, 5 and 7 are the multiples of their lowest common multiple which is 105. ie their common multiples are all the multiples of 105, of which there is no end - there is an infinite number of multiples of 105 (or any other number [except zero]).
Here are all 13 of them: 15, 30, 45, 60, 75, 90, 105, 120, 135, 150, 165, 180, 195
Since all 3 are prime numbers LCM = 3 * 5 * 7 = 105 All multiples of 105 are multiples of 3, 5 and 7
7,14,21,28,35,42,49,56,63,70,77,84,91
8,16,24,32,40,48,56,64,72,80,88,96
2,4,6,8,10,12,14,16,18,20,22,24,26,and 28
Every multiple of 525 is a multiple of both 25 and 105.
3. All other multiples of 3 are not prime.
All nonzero numbers have an infinite amount of multiples.
Multiples of 7 that are less than 60 are 7, 14, 21, 28, 35, 42, 49, 56.Multiples of 14 that are less than 60 are 14, 28, 42, 56. Common multiples that are less than 60 are 14, 28, 42, and 56.