# What is the HCF of 135 and 255?

HCF (135, 255) is the largest possible number which divides both the numbers exactly without leaving any remainder.

## Answer: HCF of 135 and 255 is 15

Let us find HCF of 135 and 255

## Explanation:

The highest common factor of two numbers is the largest possible number which divides both the numbers exactly without any remainder. It is also called the greatest common factor (GCF) or the greatest common divisor(GCD).

We will use the following two methods to find the HCF of 135 and 255.

- HCF of 135 and 255 by Prime factorization Method
- HCF of 135 and 255 by Listing Method

### Method 1: Find HCF of 135 and 255 by Prime Factorization

In this method, we represent 135 and 255 as a product of its prime factors.

Prime factorization of 135 is 3 × 3 × 3 × 5

Prime factorization of 255 is 3 × 5 × 17

Common factors of 135 and 255 are 3 and 5

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

HCF of 135 and 255 is 3 × 5 = 15

### Method 2: HCF of 135 and 255 by Listing the Common Factors

In this method, we list all the factors of 135 and 255, then identify the common factors.

The highest among the common factors is the HCF of 135 and 255.

Factors of 135 are **1**, **3**, **5**, 9, **15**, 27, 45, 135

Factors of 255 are **1**, **3**, **5**, **15**, 17, 51, 85, 255

Common factors of 135 and 255 are 1, 3, 5 and 15

The highest common factor of 135 and 255 are 1, 3, 5 and 15

HCF of 135 and 255 is 15

Irrespective of the method, the HCF of 135 and 255 remains the same.