What is the greatest common factor of 9 18 and 27?

The greatest common factor of 9, 18, and 27 is 9. Since 9 is a factor of both 18 and 27, it is automatically the GCF of the set.

Factors of 9: 1, 3, 9

Factors of 18: 1, 2, 3, 6, 9, 18

Factors of 27: 1, 3, 9, 27

GCF (9, 18, 27) = 9