Answer:
The answer is 6
Explanation:
The biggest common factor number is the GCF number. So the greatest common factor 24 and 66 is 6.
Factors for 24: 1, 2, 3, 4, 6, 8, 12, and 24.
Factors for 66: 1, 2, 3, 6, 11, 22, 33, and 66.
They both have 6 in common