300, 600, 900, 1200, 1500, 1800 . . . ∞
Since 75 is a multiple of 25, all of its multiples are common.
25, 50, 75, 100
100
25, 50, 75, 100.
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.
There are 6 multiples of 15 in 100. They are: 15, 30, 45, 60, 75, and 90
50, 75, 100.
25, 50, 75, 100
They are: 60, 75 and 90
25, 50, 75, 100, 125
25, 50, 75, 100, 125.
15, 30, 45, 60, 75, 90.