30 over 108 is a fraction. A fraction does not (cannot) have a GCF.
The GCF is 12.
The GCF is 54.
The GCF is 27.
The GCF is 4.
The GCF is 108.
The GCF is 36.
GCF of 108 and 360 is 36.
GCF of 63 and 108 is 9.
Gcf = 54 lcm = 108
Oh, dude, the Greatest Common Factor (GCF) of 162, 108, and 180 is 54. It's like the biggest number that can divide all three of them without leaving a remainder. So, yeah, 54 is the cool kid in this math problem.
The GCF is 9.