Find a number between 364 and 384 that is both a multiple of 7 and a multiple of 3
So the least common multiple of 7 and 3 is 21
So the multiple between 364 and 384 should be a multiple of 21.
21 × 18 = 378
And the number that is between 364 and 384 and is a multiple of 7 and 3 is 378