What are the common factors of 4 20 and 24?

The common factors of 4, 20, and 24 are 1, 2, and 4

First find the factors that go into the numbers

The factors of 4 are 1, 2, and 4

The factors of 20 are 1, 2, 4, 5, 10, and 20

The factors of 24 are 1, 2, 3, 4, 6, 8, 12, and 24

Then find the factors that match:

The common factors are: 1, 2, 4.