What is the greatest common factor of 16 and 20?

The greatest common factor (GCF) of two numbers is the largest number that can evenly divide both numbers.

To find the GCF of 16 and 20, we need to list out all the factors of each number:

Factors of 16: 1, 2, 4, 8, 16 Factors of 20: 1, 2, 4, 5, 10, 20

The common factors of 16 and 20 are 1, 2, and 4. The greatest common factor is 4, as it is the largest number that both 16 and 20 can be divided by evenly.

Therefore, the greatest common factor of 16 and 20 is 4.