The greatest common factor of 99 and 66 is 33 because that is the highest number that BOTH numbers can be multiplied by
33 x 3 = 99
33 x 2 = 66
The greatest common factor of 99 and 66 is 33 because that is the highest number that BOTH numbers can be multiplied by
33 x 3 = 99
33 x 2 = 66