# What is the GCF of 20 and 32?

To find the GCF (Greatest Common Factor) of two numbers, we have to determine the largest possible number which divides the two numbers exactly leaving the remainder as 0.

## Answer: GCF of 20 and 32 is 4

We can explain the GCF of 20 and 32 by the following two methods.

## Methods to find GCF of 20 and 32

- Listing the common factors method
- Prime factorization Method

### Method 1: GCF of 20 and 32 by Listing the Common Factors

The list of factors of 20 and 32 is shown below.

We can observe that the common factors of 20 and 32 are 1, 2, and 4

So, the greatest common factor of 20 and 32 is 4

GCF of 20 and 32 is 4

### Method 2: GCF of 20 and 32 by Prime Factorization

Let us express the numbers, 20 and 32 as a product of its prime factors.

Prime factorization of 20 is 2 × 2 × 5

Prime factorization of 32 is 2 × 2 × 2 × 2 × 2

The common prime factors are 2 and 2

GCF of 20 and 32 is the product of the prime factors that are common to the prime factorization of 20 and 32

GCF of 20 and 32 is 4

You can find the GCF of 20 and 32 in any of the above methods but the solution will be the same.