Question: what is the greatest common factor for 3 and 27?
Answer: The prime factorization of 3 is: 3.
The prime factorization of 27 is: 3 x 3 x 3.
The prime factors and multiplicities 3 and 27 have in common are: 3.
3 is the gcf of 3 and 27.
gcf(3,27) = 3.