Q:

What is the GCF of 121 and 15?

Accepted Solution

A:
Solution: The GCF of 121 and 15 is 1 Methods How to find the GCF of 121 and 15 using Prime Factorization One way to find the GCF of 121 and 15 is to compare the prime factorization of each number. To find the prime factorization, you can follow the instructions for each number here: What are the Factors of 121? What are the Factors of 15? Here is the prime factorization of 121: 1 1 2 11^2 1 1 2 And this is the prime factorization of 15: 3 1 × 5 1 3^1 × 5^1 3 1 × 5 1 When you compare the prime factorization of these two numbers, you can see that there are no matching prime factors. When this is the case, it means that there are no common factors between these two numbers. As a result, the GCF of 121 and 15 is 1. Thus, the GCF of 121 and 15 is: 1 How to Find the GCF of 121 and 15 by Listing All Common Factors The first step to this method of finding the Greatest Common Factor of 121 and 15 is to find and list all the factors of each number. Again, you can see how this is done by looking at the “Factors of” articles that are linked to above. Let’s take a look at the factors for each of these numbers, 121 and 15: Factors of 121: 1, 11, 121 Factors of 15: 1, 3, 5, 15 When you compare the two lists of factors, you can see that the only common factor is 1. So, in this case, the GCF of 121 and 15 is 1. Find the GCF of Other Number Pairs Want more practice? Try some of these other GCF problems: What is the GCF of 48 and 7? What is the GCF of 81 and 72? What is the GCF of 131 and 13? What is the GCF of 46 and 16? What is the GCF of 108 and 6?