Question: which number is not a common factor of 32 and 48?
Answer: The gcf of 32 and 48 can be obtained like this: The factors of 32 are 32, 16, 8, 4, 2, 1. The factors of 48 are 48, 24, 16, 12, 8, 6, 4, 3, 2, 1. The common factors of 32 and 48 are 16, 8, 4, 2, 1, intersecting the two sets above.