Is 39 a multiple of 6?

Answer 1

Not in the normal usage of the words. Usually, a number is considered to be a multiple of another number only of there is an integer you can multiply the other number by in order to get the first number. If you allowed multiplication by non-integers, then every number would be a multiple of every other number except zero and the term "multiple" would be fairly useless. So in the normal way of speaking, 39 is not a multiple of 6 because there is no integer (whole number) you can multiply 6 by in order to get 39.