Question

What are the Common multiples of 9 and 15?

Answer 1

Common multiples are `45,90,135......`.

These are all multiples of `45`, the LCM of `9` and `15`

Explanation:

Multiples of `9` are

`9,18,27,36,color(red)(45),54,63,72,81,color(red)(90),99,108,117,126,color(red)(135),..........`

and multiples of `15` are

`15,30,color(red)(45),60,75,color(red)(90),105,120,color(red)(135)..............`

Hence common multiples are `45,90,135......`

(You can check that they will all be multiples of `45`)

and Least Common Multiple is `45`