# What is the GCF of 80 and 20?

GCF (Greatest Common Factor) of 80 and 20 is the largest possible number which divides both 80 and 20 exactly.

## Answer: GCF of 80 and 20 is 20

GCF of 80 and 20 is the highest number that divides 80 and 20 exactly leaving the remainder 0.

## Explanation:

The greatest common factor of two numbers x and y is the greatest number that divides x and y leaving the remainder as 0

We will find the GCF of 80 and 20 by the following methods.

- GCF of 80 and 20 by Listing the Common Factors Method
- GCF of 80 and 20 by Prime Factorization

### Method 1: GCF of 80 and 20 by Listing the Common Factors

Common Factors of 80 and 20: 1, 2, 4, 5, 10, 20

The greatest common factor is 20

This means the GCF of 80 and 20 is 20

### Method 2: GCF of 80 and 20 by Prime Factorization

Let us represent 80 and 20 as a product of its prime factors.

Prime factorization of 80 is: 2 × 2 × 2 × 2 × 5

Prime factorization of 20 is: 2 × 2 × 5

The common prime factors are: 2, 2 and 5

GCF is the product of the prime factors that are common to each of the given numbers.

GCF of 80 and 20 is 20

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