GCF for 30 and 855

What is the Greatest Common Factor of 30 and 855?

Answer: GCF of 30 and 855 is 15

(Fifteen)

Finding GCF for 30 and 855 using all factors (divisors) listing

The first method to find GCF for numbers 30 and 855 is to list all factors for both numbers and pick the highest common one:

All factors of 30: 1, 2, 3, 5, 6, 10, 15, 30

All factors of 855: 1, 3, 5, 9, 15, 19, 45, 57, 95, 171, 285, 855

So the Greatest Common Factor for 30 and 855 is 15

Finding GCF for 30 and 855 by Prime Factorization

The second method to find GCF for numbers 30 and 855 is to list all Prime Factors for both numbers and multiply the common ones:

All Prime Factors of 30: 2, 3, 5

All Prime Factors of 855: 3, 3, 5, 19

As we can see there are Prime Factors common to both numbers: 3, 5

Now we need to multiply them to find GCF: 3 × 5 = 15

GCF Table

Number 1Number 2GCF
1585515
168551
178551
188559
1985519
208555
218553
228551
238551
248553
258555
268551
278559
288551
298551
3085515
318551
328551
338553
348551
358555
368559
378551
3885519
398553
408555
418551
428553
438551
448551

About "Greatest Common Factor" Calculator

This calculator will help you find the greatest common factor (GCF) of two numbers. For example, it can help you find out what is the Greatest Common Factor of 30 and 855? (The answer is: 15). Select the first number (e.g. '30') and the second number (e.g. '855'). After that hit the 'Calculate' button.
Greatest Common Factor (GCF) also known as the Greatest Common Divisor (GCD) or Highest Common Factor (HCF) - it is the largest positive integer that divides each of the integers with zero remainder

FAQ

What is the Greatest Common Factor of 30 and 855?

GCF of 30 and 855 is 15