Greatest Common Factor of 72 and 78

GCF(72, 78) = 6, Greatest common factor of 72 and 78 is 6. Greatest Common Factor or Greatest Common Divisor of two numbers is the largest integer by which both the numbers can be divided. There are two different methods to calculate Greatest Common Factor of 72 and 78. Greatest Common Factor by prime factorization method and Greatest Common Factor by matching factors method.

Greatest Common Factor of 72 and 78 by prime factorization method

We will first find the prime factorization of 72 and 78.
Prime Factorization of 72 is 1, 2, 2, 2, 3, 3 and Prime Factorization of 78 is 1, 2, 3, 13.

  • Factorize\( (72) = \) \(1\times 2\times 2\times 2\times 3\times 3\)
  • Factorize\( (78) = \) \(1\times 2\times 3\times 13\)
Now we need to find any which are common for each number (1, 2, 3) and multiply these numbers together.
\(GCF(72, 78) = 1\times 2\times 3 = 6\).

Greatest Common Factor of 72 and 78 by matching factors method

List of positive integers factors of 72 leaving a remainder zero is 1, 2, 3, 4, 6, 8, 9, 12, 18, 24, 36, 72
List of positive integers factors of 78 leaving a remainder zero is 1, 2, 3, 6, 13, 26, 39, 78
As you can see, 6 is the greatest and common number that 72 and 78 divides into.
So the greatest common factor 72 and 78 is 6.
\(GCF(72, 78) = 6\).

If you want to learn more about greatest common divisor, take a look at the Wikipedia page.
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