What is the GCF of 18 and 20?
The largest possible number which divides the given numbers exactly without any remainder is called the Greatest Common Factor.
Answer: The GCF of 18 and 20 is 2
Two methods to find the GCF of 18 and 20 are explained below.
Methods to find GCF of 18 and 20
We can find the GCF by the following methods
- Prime factorization Method
- Listing the common factors method
Calculate GCF of 18 and 20 by Prime Factorization
Let us represent 18 and 20 as a product of its prime numbers.
Prime factorization of 18 is 2 × 3 × 3
Prime factorization of 20 is 2 × 2 × 5
The common factor in the prime factorization of 18 and 20 = 2
GCF is the product of the factors that are common to each of the given numbers.
So, GCF of 18 and 20 is 2
Calculate GCF of 18 and 20 by Listing the Common Factors
The factors of 18 and 20 are shown below.
Clearly, the common factors of 18 and 20 are 1 and 2
The greatest common factor of 18 and 20 is 2
You can find the GCF in any of the above methods but the solution will be the same.