Solution: The GCF of 27 and 35 is 1MethodsHow to find the GCF of 27 and 35 using Prime FactorizationOne way to find the GCF of 27 and 35 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 27?What are the Factors of 35?Here is the prime factorization of 27:333^333And this is the prime factorization of 35:51×715^1 × 7^151×71When 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 27 and 35 is 1.Thus, the GCF of 27 and 35 is: 1How to Find the GCF of 27 and 35 by Listing All Common FactorsThe first step to this method of finding the Greatest Common Factor of 27 and 35 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, 27 and 35:Factors of 27: 1, 3, 9, 27Factors of 35: 1, 5, 7, 35When you compare the two lists of factors, you can see that the only common factor is 1. So, in this case, the GCF of 27 and 35 is 1.Find the GCF of Other Number PairsWant more practice? Try some of these other GCF problems:What is the GCF of 18 and 98?What is the GCF of 70 and 73?What is the GCF of 144 and 67?What is the GCF of 60 and 139?What is the GCF of 40 and 34?