# What is the GCF of 42 and 54 ?

The greatest common factor of two or more non-zero integers, x & y, is the greatest positive integer m, which divides both, x & y

## Answer: The GCF of 42 and 54 is 6

Let us see how to find the GCF of 42 and 54

## Explanation:

We have multiple ways to calculate the GCF of 42 and 54

- Prime factorization
- Listing common factors of 42 and 54

### Method 1: Prime factorization

Let's prime factorize the numbers 42 and 54 as shown below

GCF is the product of all the common factors of 42 and 54 taken once

Hence, GCF(42,54) = 3 × 2 = 6

### Method 2 : Listing common factors of 42 and 54

In this method, all the factors of 42 and 54 will be listed and the greatest factor that is common to them will be chosen as the GCF

According to the factors of 42 and factors of 54

Factors of 42: 1, 2, 3, 6, 7, 14, 21, 42

Factors of 54: 1, 2, 3, 6, 9, 18, 27, 54

We see that their greatest common factor is 6

Hence, GCF(42,54) is equal to 6