# What is the GCF of 3 and 20?

GCF (Greatest Common Factor) of two numbers is the largest possible number that divides the two numbers exactly without leaving any remainder.

## Answer: GCF of 3 and 20 is 1

GCF of 3 and 20 is the highest number that divides 3 and 20 exactly leaving the remainder 0.

## Explanation:

We can find the GCF of 3 and 20 by the following two methods.

- Long Division method
- Prime factorization Method

### Method 1: GCF of 3 and 20 by Long Division

**Step 1:** Divide 20 by 3 and check the remainder. Here, the remainder is 2.

**Step 2:** Make the remainder 2 as the divisor and the divisor 3 as the dividend and perform the long division again.

**Step 3:** Continue till you get the remainder as 0 and GCF (3, 20) will the last divisor of the division process.

So, the GCF of 3 and 20 is 1.

### Method 2: GCF of 3 and 20 by Prime Factorization

We will express the numbers 3 and 20 as a product of their prime factors.

Prime factorization of 3 is 3

Prime factorization of 20 is 2 × 2 × 5

There's no common prime factor of 3 and 20.

So, GCF of 3 and 20 is 1.

Also, the GCF of two co-prime numbers is always 1.

Since 3 and 20 are co-prime numbers, their GCF is 1.

You can find the GCF in any of the above methods but the solution will be the same.