# What is the Greatest Common Factor of 30 and 40?

Greatest common factor (GCF) of 30 and 40 is 10.

GCF(30,40) = 10

We will now calculate the prime factors of 30 and 40, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 30 and 40.

GCF Calculator and
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## How to find the GCF of 30 and 40?

We will first find the prime factorization of 30 and 40. After we will calculate the factors of 30 and 40 and find the biggest common factor number .

### Step-1: Prime Factorization of 30

Prime factors of 30 are 2, 3, 5. Prime factorization of 30 in exponential form is:

30 = 21 × 31 × 51

### Step-2: Prime Factorization of 40

Prime factors of 40 are 2, 5. Prime factorization of 40 in exponential form is:

40 = 23 × 51

### Step-3: Factors of 30

List of positive integer factors of 30 that divides 30 without a remainder.

1, 2, 3, 5, 6, 10, 15

### Step-4: Factors of 40

List of positive integer factors of 40 that divides 30 without a remainder.

1, 2, 4, 5, 8, 10, 20

#### Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 30 and 40. The biggest common factor number is the GCF number.
So the greatest common factor 30 and 40 is 10.

Also check out the Least Common Multiple of 30 and 40