There is an infinite number of common multiples for 60 and 45. A common multiple of any two or more numbers is any number into which each of two or more numbers can be divided evenly (zero remainder). However, the least or lowest common multiple of 60 and 45 is 180.
180, 360, 540 and so on.
The multiples of 15 are 15, 30, 45, 60, 75 and so on. For them to be common, they need to be compared to another set of multiples.
The first 3 common multiples of 4 and 5 are: 20, 40, and 60.
15, 30, 45
15, 30, 45 and 60
15, 30, 45
They are: 15, 30, 45, 60.
15, 30, 45, 60
15, 30, 45, 60 and so on.
3 examples of common multiples of 34 and 5 are 170, 1700, and 17000170.
Since the lowest common multiple of 3 and 5 is 15, the common multiples of 3 and 5 are the multiples of 15: 30, 45, 60, 75, 90, etc...
Any multiple of the LCM (15) is common.
The common multiples of 3 and 15 from 1 to 100 are 15, 30, 45, 60, 75, and 90.