What is the greatest common factor of 27 and 45?

The greatest common factor (GCF) of 27 and 45 is 9.

To find the GCF, you can list the factors of each number and find the largest one they have in common.

Factors of 27: 1, 3, 9, 27 Factors of 45: 1, 3, 5, 9, 15, 45

The only common factor of both 27 and 45 is 9, which is therefore the GCF.

Another way to find the GCF is to use prime factorization.

27 = 3 x 3 x 3 45 = 3 x 3 x 5

The GCF is the product of the common prime factors, which in this case is 3 x 3 = 9.