Not sure what the GFC is but if you meant GCF, the answer is no, it is never even.
No, their GCF is always odd.
Two odd numbers always sum to an even number. Always. Two even numbers always sum to an even number, and an odd number and an even number always sum to an odd number.
No, always odd.
The GCF will, yes.
The GCF is, yes.
The GCF is, yes.
Always odd.
No, always odd.
No, always odd.
All even numbers can be divided by two, while odd numbers can't. Also, an even number plus an even number is always even. An odd number plus an odd number is always even. An even number plus an odd number is always odd.
Your question is incomplete. Adding an even number with an odd number will always result in an odd number. Multiplying an even number with an odd number will always result in an even number.
"IT IS ALWAYS A ODD"