What is the greatest common factor of 9 and 16?

The GCF of 9 and 16 is 1 because it is the only factor shared by both numbers, and thus is the greatest.

The p rime factorization of 9 = 3x3

The prime factorization of 16 = 2x2x2x2

Nothing is common from the prime factorization of both numbers.

Therefore, Greatest Common Factor is 1.
The greatest common factor of 9 and 16 is 1.