What is the greatest common factor of 24 and 40?

The greatest common factor of 24 and 40 is 8.

To find the GCF, list the factors of each number:

24 - 1, 2, 3, 4, 6, 8, 12, 24

40 - 1, 2, 4, 5, 8, 10, 20, 40
The GCF is 8.