Solutions by » GCF of two numbers

What is the GCF of 5 and 15?

The GCF of 5 and 15 is 5.

Steps to find GCF

  1. Find the prime factorization of 5
    5 = 5
  2. Find the prime factorization of 15
    15 = 3 × 5
  3. To find the GCF, multiply all the prime factors common to both numbers:

    Therefore, GCF = 5

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The greatest common factor (GCF) is also known as greatest common divisor (GCD) or highest common factor (HCF).