Question: what is the common factor for 9 and 36?
Answer: The gcf of 9 and 36 can be obtained like this: The factors of 9 are 9, 3, 1. The factors of 36 are 36, 18, 12, 9, 6, 4, 3, 2, 1. The common factors of 9 and 36 are 9, 3, 1, intersecting the two sets above.