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GCF of 7, 15, 21

Created By : Veerendra
Reviewed By : Phani Ponnapalli
Last Updated at : Mar 29,2023

Are you looking for a way to calculate the greatest common factor of 7, 15, 21 ? Well, you’re in luck! In this article, we will be showing you how to use two different methods to find the GCF of 7, 15, 21. We also provide a free GCF of Two or More Numbers Calculator to obtain instant results.

 

GCF of:

Detailed Solution to Find GCF of 7, 15, 21

Given numbers are 7, 15, 21
The greatest common factor of 7, 15, 21 can be found by using the following 2 different methods.
The GCF of 7, 15, 21 is 1.

GCF of 7,15,21 Using Prime Factorization Method

Prime factorization is basically division by prime numbers only. Keep dividing all numbers by the same prime number, until the numbers can no longer be divided by a single prime number. Then, multiply all the prime numbers that are on the left side.

∴ GCF of numbers is 1 because of no common factors present between them.

How to Find the Greatest Common Factor of 7,15,21 using the Common Factor Method?

The common factor method requires listing down all the factors of 7,15,21 that divide each of these numbers without leaving a remainder. To begin, let us list down the factors

list down the factors of 7

1,7

list down the factors of 15

1,3,5,15

list down the factors of 21

1,3,7,21

Greatest Common Factor

Once you have listed down the factors, all you have to do is look for the highest factor that appears in all the three aforementioned lists. The greatest number that we can see in all lists is 1 . Therefore, the GCF of 7,15,21 is 1

Frequently Asked Questions on GCF of 7, 15, 21

1. What is the GCF of 7, 15, 21 ?

Answer: GCF of 7, 15, 21 is 1.

2. How to calculate the GCF of 7, 15, 21 ?

Answer: You can use two different methods: listing down the factors, and prime factorization. If you want to use the listing method, then simply write down all the factors of 7, 15, 21. Then, select the greatest number that appears in lists. From this, you will see that the GCF is 1. Next, you can also use the prime factorization method to divide the numbers by prime numbers. Then, multiply the prime numbers on the side to get your answer, which is 1.