140, 280, 420, 560, 700
The first 5 multiples of 4 and 20 are 20, 40, 60, 80, 100
They are 10 and 20
15 & 20 have an infinite number of Common Multiples; the first three are 60, 120 and 180.
20, 40 and 60
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 4 are 4, 8, 12, 16 and 20. For them to be common, they need to be compared to another set of multiples.
They are the first five multiples of their lowest common multiple: 140, 280, 420, 560, 700.
1, 660, 5580
20 and 40.
Any multiples of 20.
The LCM is 20
the first three common multiples of 7, 20, and 35 are 140, 280, and 420