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GCF of 840, 1780

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 840, 1780 ? Well, you’re in luck! In this article, we will be showing you how to use two different methods to find the GCF of 840, 1780. We also provide a free GCF of Two or More Numbers Calculator to obtain instant results.

 

GCF of:

Detailed Solution to Find GCF of 840, 1780

Given numbers are 840, 1780
The greatest common factor of 840, 1780 can be found by using the following 2 different methods.
The GCF of 840, 1780 is 20.

GCF of 840,1780 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.

2 840, 1780
2 420, 890
5 210, 445
42, 89

∴ Thus, the GCF of given numbers is 2 x 2 x 5 = 20

How to Find the Greatest Common Factor of 840,1780 using the Common Factor Method?

The common factor method requires listing down all the factors of 840,1780 that divide each of these numbers without leaving a remainder. To begin, let us list down the factors

list down the factors of 840

1,2,3,4,5,6,7,8,10,12,14,15,20,21,24,28,30,35,40,42,56,60,70,84,105,120,140,168,210,280,420,840

list down the factors of 1780

1,2,4,5,10,20,89,178,356,445,890,1780

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 20 . Therefore, the GCF of 840,1780 is 20

Frequently Asked Questions on GCF of 840, 1780

1. What is the GCF of 840, 1780 ?

Answer: GCF of 840, 1780 is 20.

2. How to calculate the GCF of 840, 1780 ?

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 840, 1780. Then, select the greatest number that appears in lists. From this, you will see that the GCF is 20. 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 20.