What is the greatest common factor of 12 18 and 27?

The GCF of 12, 18, and 27 is 3

The factors of 12 = 1x12, 2x6, 3x4 = 1, 2, 3, 4, 6, and 12

The factors of 18 = 1x18, 2x9, 3x6 = 1, 2, 3, 6, 9, and 18

The factors of 27 = 1x27, 3x9 = 1, 3, 9, and 27

The GCF is 3.