The work that Ryan did to find the greatest common factor of 48 and 72 is shown below. Prime factorization of 48: 2, 2, 2, 2, 3
Prime factorization of 72: 2, 2, 2, 3, 3

The greatest common factor is 2 ´ 2 ´ 2 ´ 2 ´ 3 ´ 3.

What is Ryan’s error?
Ryan did not include all the common factors in the greatest common factor.
Ryan did not list all the factors in the prime factorization of 48.
Ryan did not list all the factors in the prime factorization of 72.
Ryan found the least common multiple.