How to Find the Greatest Common Factor for 15 and 20

You can find the greatest common factor (GCF) of 15 and 20 by listing the common factors for each number and then identifying the greatest factor in each list. Here's the step-by-step process: Step 1: List the Factors of 15 • The factors of 15 are the numbers that can evenly divide 15. In this case, they are 1, 3, 5, and 15. Step 2: List the Factors of 20 • The factors of 20 are the numbers that can evenly divide 20. In this case, they are 1, 2, 4, 5, 10, and 20. Step 3: Identify the Common Factors • Compare the lists of factors for 15 and 20 to find the common factors. The common factors are the numbers that appear in both lists. Common Factors: 1, 5 Step 4: Determine the Greatest Common Factor • Finally, determine which common factor is the greatest. In this case, the greatest common factor (GCF) of 15 and 20 is 5. So, the GCF of 15 and 20 is 5. Note: You can also use prime factorization to find the GCF. It involves breaking down each number into its prime factors and then finding the common prime factors.