What are the numbers with the greatest common factor of five?

Answer 1

There can be no numbers which have 5 as their greatest common multiple. If 5 is a common multiple then 10, 15, 20, ... are all common multiples and the are all greater than 5. So 5 cannot be the greatest common multiple.

In fact, once you find the least common multiple of a set of numbers, you can keep adding the LCM to itself over and over again. Each new number you get will be a common multiple of your set of numbers, but each new number will always be larger than the previous. This means that you can keep adding while the number approaches infinity and you will still never find a greatest multiple.

Answer 2

5 and 15 are an example

5 and 25 are an example

there are infinite examples

Answer 3

There are none. The greatest common multiple of any set of integers is infinite.