What is the highest common multiple of 30 and 45?

Answer 1

The lowest common multiple is 90 .

There is no highest one. If you think you've found the highest one,

just add 90 to it, and you'll have a higher common multiple. You can

continue doing that forever.

Answer 2

The highest common multiple of any set of integers is infinite.

Answer 3

The least common factor of any set of integers is 1.

Answer 4

15

Answer 5

15.