Greatest Common Factor of 28 and 392

GCF(28, 392) = 28, Greatest common factor of 28 and 392 is 28. 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 28 and 392. Greatest Common Factor by prime factorization method and Greatest Common Factor by matching factors method.

Greatest Common Factor of 28 and 392 by prime factorization method

We will first find the prime factorization of 28 and 392.
Prime Factorization of 28 is 1, 2, 2, 7 and Prime Factorization of 392 is 1, 2, 2, 2, 7, 7.

  • Factorize\( (28) = \) \(1\times 2\times 2\times 7\)
  • Factorize\( (392) = \) \(1\times 2\times 2\times 2\times 7\times 7\)
Now we need to find any which are common for each number (1, 2, 2, 7) and multiply these numbers together.
\(GCF(28, 392) = 1\times 2\times 2\times 7 = 28\).

Greatest Common Factor of 28 and 392 by matching factors method

List of positive integers factors of 28 leaving a remainder zero is 1, 2, 4, 7, 14, 28
List of positive integers factors of 392 leaving a remainder zero is 1, 2, 4, 7, 8, 14, 28, 49, 56, 98, 196, 392
As you can see, 28 is the greatest and common number that 28 and 392 divides into.
So the greatest common factor 28 and 392 is 28.
\(GCF(28, 392) = 28\).

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