The total number of integers that are multiples of both 12 and 28 is infinite. Here are the first few: 84, 168, 252, 336, 420, 504, 588, 672, 756, 840 . . .
84, 168, 252
84, 168, 252
84, 168, 252
84, 168, 252
the least common multiple is 84
84, 168, 252.
12, 24, 36, 49, 60, 72, 84 28, 56, 84
14, 28, 42
84, 168, 252
Multiples of 6: 12, 18, 24 Multiples of 7: 14, 21, 28
The multiples of 28 include 28, 56 and 84. For them to be common, they need to be compared to another set of multiples.
280, 560, 840