What is the GCF of 15 and 20?
Greatest Common Factor of two or more numbers is the largest possible number which divides the given numbers exactly without any remainder.
Answer: GCF of 15 and 20 is 5
We can find the GCF by the following methods.
Methods to find GCF of 15 and 20
- Prime factorization Method
- Listing the common factors method
- Long division Method
Method 1: GCF of 15 and 20 by Prime Factorization
Let us represent 15 and 20 as a product of its prime numbers.
GCF is the product of the factors that are common to each of the given numbers.
GCF of 15 and 24 is 5
Method 2: GCF of 15 and 20 by Listing the Common Factors
Common Factors of15 and 20: 1, 5. greatest among them is 5.
Therefore, GCF of 15 and 20 is 5
Method 3: GCF of 15 and 20 by Long Division
- Step 1: Divide 20 by 15 and check the remainder.
- Step 2: Make the remainder of the above step as the divisor and the divisor of the above step as the dividend and perform the long division again.
- Step 3: Continue till you get remainder as 0
You can find the GCF in any of the above methods but the solution will be the same.