# What is the GCF of 4 and 15?

GCF of two numbers 4 and 15 is the largest possible number which divides both the numbers exactly.

## Answer: GCF of 4 and 15 is 1

Let us find GCF of 4 and 15

## Explanation:

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

The following two methods are used to find the GCF of 4 and 15.

- GCF of 4 and 15 by Prime factorization Method
- GCF of 4 and 15 by Listing Method

### Method 1: Find GCF of 4 and 15 by Prime Factorization

In this method, we represent 4 and 15 as a product of its prime factors.

Prime factorization of 4 is 2 × 2

Prime factorization of 15 is 3 × 5

The common factor of 4 and 15 is 1

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

GCF of 4 and 15 is 1

### Method 2: GCF of 4 and 15 by Listing the Common Factors

In this method, we list all the factors of 4 and 15, then identify the common factors.

The highest among the common factors is the GCF of 4 and 15.

The factors of 4 are 1, 2, and 4

The factors of 15 are 1, 3 5, and 15

Common Factor of 4 and 15 is 1.

The greatest common factor of 4 and 15 is 1

GCF of 4 and 15 is 1

Irrespective of the method, the GCF of 4 and 15 is the same as 1. They are co-primes.