140, 280, 420, 560, 700
The first 5 multiples of 4 and 20 are 20, 40, 60, 80, 100
They are 10 and 20
10, 20, 30 The common multiples of 5 and 10 are multiples of their lowest common multiple. The lcm of 5 and 10, is 10. Thus the first three common multiples are 10, 20, 30.
The first five multiples of 5 are 5, 10, 15, 20 and 25. For them to be common, they need to be compared to another set of multiples.
20 and 40.
The LCM is 20
10, 20, 30
10, 20, 30.
10, 20, 30.
20 30 40
10, 20, 30
Yes.