Suzanne A. answered 01/16/13
Encouraging elementary math tutor with 6+ years of tutoring experience
Factors are numbers you multiply together to get another number.
The factors of 11 are: 1 and 11
The factors of 33 are: 1, 3, 11, and 33 (because 1x33= 33, and 3x11=33)
Therefore, the greatest common factor is the largest factor that both numbers have in common and in this case the greatest common factor is 11.