The GCF of one number is itself.
The denominator for any whole number is 1.
If you mean the three numbers, 12, 16, and 18 - try it out! Use a calculator to check whether 122 + 162 = 182 or not.
The GCF is 6.
The GCF is 9.
The GCF is 4.
The GCF is 30.
50
The GCF of 125, 200 is 25.
The GCF is 5.
The GCF is 2.
The GCF is 3.
The GCF is 27.