# What is the HCF of 8 and 20?

HCF of 8 and 20 is the greatest possible number which divides both 8 and 20 exactly.

## Answer: HCF of 8 and 20 is 4

We will explain two methods to find the Highest Common Factor of 8 and 20

## Explanation

The highest common factor of two numbers x and y is defined to be the largest number that divides x and y leaving 0 as the remainder.

- Listing the Factors to find HCF of 8 and 20
- Prime factorization to find HCF of 8 and 20

### Method 1: HCF of 8 and 20 by Listing the Common Factors

Let us list the factors and identify the greatest among the common factors of 8 and 20.

Common Factors of 8 and 20: 2, 4

Since the greatest common factor is 4, the HCF of 8 and 20 is 4

HCF of 8 and 20 is 4

### Method 2: HCF of 8 and 20 by prime factorization

Prime factorization of 8: 2 × 2 × 2

Prime factorization of 20: 2 × 2 × 5

The product of all common prime factors is the GCF of 8 and 20

Here the common prime factors are 2 and hence GCF(8, 20) is 4