What is the greatest common multiple of 7 and 56?

Answer 1

56 is a multiple of 7, and 56 is also a multiple of itself, so 56 is

the least common multiple of both numbers.

There is no greatest common multiple. Whatever multiple you name,

no matter how large it is, I can always add 56 to it and come up with

a larger one.

Answer 2

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