150
150 is the least common multiple
150
Since 150 is a multiple of 5 and there are no lower multiples of 150 than 150, 150 is the LCM of 5 and 150.
Since 450000 is a multiple of 150, any of its multiples are common.
30, 60, 90, 120, 150, 180 . . .
30, 60, 90, 120, 150.
The common multiples of 6 and 5 are 30, 60, 90, 120, 150, 180, and so on.
The LCM of 25, 50, and 75 is 150. The multiples of 25 are 25, 50, 75, 100, 125, 150, and so on. The multiples of 50 are 50, 100, 150, and so on. The multiples of 75 are 75, 150, and so on. So the LCM is 150.
The multiples of 75: 75, 150, 225, 300, 375, 450, 525, 600, 675, 750, 825, ... The multiples of 250: 250, 500, 750, 1000, ... The least common multiple is the number in both lists that is the least. For 75 and 250, the least common multiple is 750.
Multiples of 50 include 50, 100 and 150. For them to be common, they need to be compared to another set of multiples.
Common multiples include 75, 150, 225 and so on.