Q:

What is the GCF of 55 and 121?

Accepted Solution

A:
Solution: The GCF of 55 and 121 is 11 Methods How to find the GCF of 55 and 121 using Prime Factorization One way to find the GCF of 55 and 121 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 55? What are the Factors of 121? Here is the prime factorization of 55: 5 1 × 1 1 1 5^1 × 11^1 5 1 × 1 1 1 And this is the prime factorization of 121: 1 1 2 11^2 1 1 2 When you compare the prime factorization of these two numbers, you can see that there are matching prime factors. You can now find the Greatest Common Factor of 55 and 121 by multiplying all the matching prime factors to get a GCF of 55 and 121 as 121: Thus, the GCF of 55 and 121 is: 121 How to Find the GCF of 55 and 121 by Listing All Common Factors The first step to this method of finding the Greatest Common Factor of 55 and 121 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, 55 and 121: Factors of 55: 1, 5, 11, 55 Factors of 121: 1, 11, 121 When you compare the two lists of factors, you can see that the common factor(s) are 1, 11. Since 11 is the largest of these common factors, the GCF of 55 and 121 would be 11. Find the GCF of Other Number Pairs Want more practice? Try some of these other GCF problems: What is the GCF of 90 and 67? What is the GCF of 108 and 6? What is the GCF of 30 and 72? What is the GCF of 118 and 149? What is the GCF of 71 and 107?