What is the Greatest Common Factor of 285 and 305?

Greatest common factor (GCF) of 285 and 305 is 5.

GCF(285,305) = 5

We will now calculate the prime factors of 285 and 305, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 285 and 305.

How to find the GCF of 285 and 305?

We will first find the prime factorization of 285 and 305. After we will calculate the factors of 285 and 305 and find the biggest common factor number .

Step-1: Prime Factorization of 285

Prime factors of 285 are 3, 5, 19. Prime factorization of 285 in exponential form is:

285 = 3¹ × 5¹ × 19¹

Step-2: Prime Factorization of 305

Prime factors of 305 are 5, 61. Prime factorization of 305 in exponential form is:

305 = 5¹ × 61¹

Step-3: Factors of 285

List of positive integer factors of 285 that divides 285 without a remainder.

1, 3, 5, 15, 19, 57, 95

Step-4: Factors of 305

List of positive integer factors of 305 that divides 285 without a remainder.

1, 5, 61

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 285 and 305. The biggest common factor number is the GCF number.
So the greatest common factor 285 and 305 is 5.

Also check out the Least Common Multiple of 285 and 305