Question: what is the greatest common factor in 6 33?
Answer: The factors of 6 are 6, 3, 2, 1. The factors of 33 are 33, 11, 3, 1. The common factors of 6 and 33 are 3, 1, intersecting the two sets above. In the intersection factors of 6 ∩ factors of 33 the greatest element is 3. Therefore, the greatest common factor of 6 and 33 is 3.