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.
10, 20, 30.
The LCM is 20
20, 40, 60
20, 40 and 60
10, 20, 30.
20 30 40
10, 20, 30
20, 40, 60
10, 20, 30
20, 40, 60