# What is the HCF of 18 and 60?

The highest or greatest common factor(HCF) of two numbers 18 and 60 is the largest possible number which divides both the numbers exactly.

## Answer: HCF of 18 and 60 is 6

The highest common factor of two numbers is the largest possible number which divides both the numbers exactly without any remainder

## Explanation:

Let us try to find HCF of 18 and 60 by the following methods:

- Prime factorization Method
- Listing the common factors method

### Method 1: HCF of 18 and 60 by Prime Factorization

In this method, we represent 18 and 60 as a product of its prime numbers

Prime factorization of 18 is 2 × 3 × 3

Prime factorization of 60 is 2 × 2 × 3 × 5

Common factor = 2, 3

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

HCF = 2 × 3 = 6

### Method 2: HCF of 18 and 60 by Listing the Common Factors

The process is to list all the factors of 18 and 60, then identify the common factors.The highest among the common factors is the HCF of 18 and 60.

The factors of 18 are given by 1, 2, 3, 6, 9,18

The factors of 60 are given by 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, 60

Common Factors of 18 and 60: 1, 2, 3, 6.

Greatest common factor= 6

HCF of 18 and 60 is 6