Created By : Jatin Gogia
Reviewed By : Rajasekhar Valipishetty
Last Updated : Apr 06, 2023
Make use of GCF Calculator to quickly find the Greatest Common Factor of numbers 8, 20 i.e. 4 largest integer by which both the numbers can be divided.
Greatest common factor (GCF) of 8 and 20 is 4.
GCF(8,20) = 4
Greatest common factor or Greatest common divisor (GCD) can be calculated in following way;
Prime Factorization of 8
2 | 8 |
2 | 4 |
2 | 2 |
1 |
Prime factors of 8 are 2. Prime factorization of 8 in exponential form is:
8 = 23
Prime Factorization of 20
2 | 20 |
2 | 10 |
5 | 5 |
1 |
Prime factors of 20 are 2.Prime factorization of 20 in exponential form is:
20 = 22×51
∴ So by taking common prime factors GCF of 8 and 20 is 4
Factors of 8
List of positive integer factors of 8 that divides 8 without a remainder.
1,2,4,8
Factors of 20
List of positive integer factors of 20 that divides 20 without a remainder.
1,2,4,5,10,20
Greatest Common Factor
We found the factors and prime factorization of 8 and 20. The biggest common factor number is the GCF number.
So the greatest common factor 8 and 20 is 4.
Also check out the Least Common Multiple of 8 and 20
(i) The GCF of 8 and 20 is associative
GCF of 8 and 20 = GCF of 20 and 8
1. What is the GCF of 8 and 20?
Answer: GCF of 8 and 20 is 4.
2. What are the Factors of 8?
Answer: Factors of 8 are 1, 2, 4, 8. There are 4 integers that are factors of 8. The greatest factor of 8 is 8.
3. What are the Factors of 20?
Answer: Factors of 20 are 1, 2, 4, 5, 10, 20. There are 6 integers that are factors of 20. The greatest factor of 20 is 20.
4. How to Find the GCF of 8 and 20?
Answer:
Greatest Common Factor of 8 and 20 = 4
Step 1: Find the prime factorization of 8
8 = 2 x 2 x 2
Step 2: Find the prime factorization of 20
20 = 2 x 2 x 5
Step 3: Multiply those factors both numbers have in common in steps i) or ii) above to find the gcf:
GCF = 2 x 2 = 4
Step 4: Therefore, the greatest common factor of 8 and 20 is 4