It can be and it is.
It can be and is.
Yes, the greatest common factor is less than or equal to the smallest coefficient. For example, the greatest common factor of 38 and 8 is 2.
Yes, the greatest common factor of 16 and 42 can be and is less than 16. The GCF of 16 and 42 is 2..
When they have a factor in common greater than one.
It can be and is.
6
It isn't.
The LCM will never be less than the GCF.
Since 16 is not a factor of 40, the GCF must be less than 16.
254 cannot have a greatest common factor. To have a greatest common factor, there must be more than one number involved
Lots of numbers are NOT common factors. For example, 5, 7, 100...Get the greatest common factor of both numbers. All common factors are factors of this greatest common factor. Note that all of them must needs be less than or equal to the greatest common factor. Any other number is NOT a common factor.