The greatest common factor (GCF) of 12, 18, and 26 is: 2
Since the lowest number is 12, you should only include factors up to 12.
Factors of 12: 1, 2, 3, 4, 6, 12
Factors of 18: 1, 2, 3, 6, 9
Factors of 26: 1, 2
The common factors between the three numbers are 1 and 2, but you are looking for the greatest common factor. The greatest means the highest, and which is the highest number out of 1 and 2? 2, so that is your answer.
