gcf of 21 and 40

Understand the Problem

The question is asking to find the greatest common factor (GCF) of the numbers 21 and 40. This involves identifying the largest number that can divide both 21 and 40 without leaving a remainder.

Answer

The GCF of 21 and 40 is $1$.

Steps to Solve

List the Factors of Each Number

First, we will list all the factors of 21 and 40.

The factors of 21 are: 1, 3, 7, 21
The factors of 40 are: 1, 2, 4, 5, 8, 10, 20, 40

Identify the Common Factors

Next, we need to identify which factors are common to both lists of factors.

Common factors of 21 and 40: 1

Determine the Greatest Common Factor

Now that we have the common factors, we will select the greatest one among them.

The greatest common factor (GCF) is 1.

The greatest common factor (GCF) of 21 and 40 is 1.

More Information

The GCF is the largest positive integer that divides the given numbers. In this case, since 21 and 40 share no other common factors except for 1, the GCF is simply 1. This indicates that 21 and 40 are relatively prime (or coprime), meaning they have no common factors other than 1.

Tips

A common mistake is to overlook the definition of the GCF and assume it must be greater than 1. Remember that two numbers can be relatively prime, which means their GCF is 1.

AI-generated content may contain errors. Please verify critical information

Thank you for voting!