What is the Greatest Common Factor of 40 and 28?
Greatest common factor (GCF) of 40 and 28 is 4.
GCF(40,28) = 4
We will now calculate the prime factors of 40 and 28, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 40 and 28.
How to find the GCF of 40 and 28?
We will first find the prime factorization of 40 and 28. After we will calculate the factors of 40 and 28 and find the biggest common factor number .
Step-1: Prime Factorization of 40
Prime factors of 40 are 2, 5. Prime factorization of 40 in exponential form is:
40 = 23 × 51
Step-2: Prime Factorization of 28
Prime factors of 28 are 2, 7. Prime factorization of 28 in exponential form is:
28 = 22 × 71
Step-3: Factors of 40
List of positive integer factors of 40 that divides 40 without a remainder.
1, 2, 4, 5, 8, 10, 20
Step-4: Factors of 28
List of positive integer factors of 28 that divides 40 without a remainder.
1, 2, 4, 7, 14
Final Step: Biggest Common Factor Number
We found the factors and prime factorization of 40 and 28. The biggest common factor number is the GCF number.
So the greatest common factor 40 and 28 is 4.
Also check out the Least Common Multiple of 40 and 28