The GCF of 42, 60 and 78 is 6. You are left with 7, 10 and 13 respectively after division. There are no further factors in common (aside from 1).
The GCF is 6.
The GCF of 42, 48, and 78 is 6.
The GCF is 6.
The GCF is 6.
The GCF of 36, 42, and 78 is 6.
The GCF of 8, 42, and 78 is 2.
The GCF of 20, 42, and 78 is 2.
The GCF is 6.
The GCF of 60 and 78 is 6.
The GCF of 24, 42, and 60 is 6.
The Greatest Common Factor of 9, 36, 72: 9