What is the greatest common factor of 36 and 60?

1 answer

To find the greatest common factor (GCF) of 36 and 60, we can start by finding the prime factorization of each number.

  1. Prime factorization of 36:

    • 36 can be divided by 2:
      \( 36 \div 2 = 18 \)
      \( 18 \div 2 = 9 \)
      \( 9 \div 3 = 3 \)
      \( 3 \div 3 = 1 \)
    • Therefore, the prime factorization of 36 is:
      \( 36 = 2^2 \times 3^2 \)
  2. Prime factorization of 60:

    • 60 can be divided by 2:
      \( 60 \div 2 = 30 \)
      \( 30 \div 2 = 15 \)
      \( 15 \div 3 = 5 \)
      \( 5 \div 5 = 1 \)
    • Therefore, the prime factorization of 60 is:
      \( 60 = 2^2 \times 3^1 \times 5^1 \)
  3. Finding the GCF:

    • We take the lowest power of all prime factors present in both factorizations:
      • For the prime factor \( 2 \): the minimum power is \( 2^2 \).
      • For the prime factor \( 3 \): the minimum power is \( 3^1 \).
    • The prime factor \( 5 \) is not common to both numbers.

So, the GCF is: \[ GCF = 2^2 \times 3^1 = 4 \times 3 = 12 \]

Thus, the greatest common factor of 36 and 60 is 12.