Can the gcf of 16 and 42 be than less 16 explain?

Answer 1

It must be less than or equal to the smallest of the set of numbers whose GCF you are trying to obtain. So it must be less than or equal to 16.

Furthermore, it is not 16 because 16 is not a factor of 42. Therefore, it must be less than 16.

Answer 2

It can and it is. 16 is not a factor of 42. 16 can't have a factor greater than itself, so the GCF must be lesser.