30 and all its multiples
6, 12, 18 and so on.
the first two common multiples of 15,27 are 135,270
105, 210
There are an infinite number of common multiples of 21 and 15 .The smallest two of them are 105 and 210 . A couple of others are 1,890 and 453,705 .
42
30 and 60
The common multiples of 2, 4, 5, 10, and 15 are the multiples of the set's LCM, which is 60. Therefore, the common multiples of 2, 4, 5, 10, and 15 are 60, 120, 180, 240, 300, 360, and so on. There is an infinite number of common multiples for 2 5 10 4 and 15. 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 (LCM) of 2 5 10 4 and 15 is 60.
They have to be multiples of 15 so all of them will be multiples of 3. They all have to be even so you are left with 30, 60, 90
30, 60, 90 and so on.
To find common multiples you need the multiples of at least 2 numbers for example: To find multiples of 15 you have to do this: 15 x 1 = 15 15 x 2 = 30 15 x 3 = 45 15 x 4 = 60 15 x 5 = 75 The first five multiples of 15 are 15, 30, 45, 60, 75 Now find the multiples of another number like lets say 9 9 x 1 = 9 9 x 2 = 18 9 x 3 = 27 9 x 4 = 36 9 x 5 = 45 The first five multiples of 9 are 9, 18, 27, 36, 45 Now compare the results of the two numbers 15 and 9 and you can see they have a common multiple of 45. Normally you want to continue finding multiples for each number until you have at least 2 common multiples.
2,and3
30 and 60 (if you count 60)