What is the GCF of 21 and 35?
GCF (Greatest Common Factor) of two numbers is the largest possible number which divides the two numbers exactly without any remainder.
Answer: GCF of 21 and 35 is 7
Two methods to find the GCF of 21 and 35 are explained below.
Methods to find GCF of 21 and 35
- GCF of 21 and 35 by Prime Factorization
- GCF of 21 and 35 by Common Factors
Method 1: GCF of 21 and 35 by Prime Factorization
Represent 21 and 35 as a product of its prime factors.
Prime factorization of 21 is 3 x 7
Prime factorization of 35 is 5 x 7
The common factor in the prime factorization of 21 and 35 is 7
GCF is the product of the factors that are common to each of the given numbers.
Since the common factor is 7, the GCF of 21 and 35 is 7
Method 2: GCF of 21 and 35 by Listing the Common Factors
There are two common factors of 21 and 35, that are, 1 and 7
So, GCF of 21 and 35 is 7
You can find the GCF in any of the above methods but the solution will be the same.