What are the common factors of 18 and 24?

1, 2, 3, and 6. They're called "common factors" of 18 and 24.
The factors of 18 are 1, 2, 3, 6, 9, and 18.
The factors of 24 are 1, 2, 3, 4, 6, 8, 12, and 24.
The common factors are 1, 2, 3, and 6.
The greatest common factor is 6.
1, 2, 3, and 6. They're called "common factors" of 18 and 24.