What is the greatest common factor of 12 16 20 and 24?

The GCF of 12, 16, 20 and 24 is 4.

Factors of 12: 1, 2, 3, 4, 6, 12.

Factors of 16: 1, 2, 4, 8, 16.

Factors of 20: 1, 2, 4, 5, 10, 20.

Factors of 24: 1, 2, 3, 4, 6, 8, 12, 24.

GCF (12, 16, 20, 24) = 4