Solution: The GCF of 78 and 119 is 1MethodsHow to find the GCF of 78 and 119 using Prime FactorizationOne way to find the GCF of 78 and 119 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 78?What are the Factors of 119?Here is the prime factorization of 78:21×31×1312^1 × 3^1 × 13^121×31×131And this is the prime factorization of 119:71×1717^1 × 17^171×171When 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 78 and 119 is 1.Thus, the GCF of 78 and 119 is: 1How to Find the GCF of 78 and 119 by Listing All Common FactorsThe first step to this method of finding the Greatest Common Factor of 78 and 119 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, 78 and 119:Factors of 78: 1, 2, 3, 6, 13, 26, 39, 78Factors of 119: 1, 7, 17, 119When you compare the two lists of factors, you can see that the only common factor is 1. So, in this case, the GCF of 78 and 119 is 1.Find the GCF of Other Number PairsWant more practice? Try some of these other GCF problems:What is the GCF of 113 and 49?What is the GCF of 96 and 123?What is the GCF of 9 and 115?What is the GCF of 10 and 87?What is the GCF of 101 and 6?