What is the greatest common factor of 10 and 9-?

The GCF of 9 and 10 is 1.

One way to determine the common factors and greatest common factor is to find all the factors of the numbers and compare them.

The factors of 9 are 1, 3, and 9.

The factors of 10 are 1, 2, 5, and 10.

The only common factor is 1. Therefore, the greatest common factor is 1, which means the numbers are relatively prime.

All consecutive integers are relatively prime and have a GCF of 1.