What is the GCF of 9 21 60?

The factors of 9 are:

1, 3, 9

The factors of 21 are:

1, 3, 7, 21

The factors of 60 are:

1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, 60

The common factors are:

1, 3

The Greatest Common Factor (GCF) is:

3