Common factors of two or more numbers are the factors which are common to all the given numbers.

For example, the factors of number 12 are 1, 2, 3, 4, 6 and 12. The factors of number 30 are 1, 2, 3, 5, 6, 10, 15 and 30. There are some factors which are common to both 12 and 30. They are 1, 2, 3, 6. These are called as the common factors of 12 and 30.

### Steps in Finding Common Factors:

- Find the factors of the given numbers.
- Find the factors which are common for the given numbers.

### Examples in Finding Common Factors

Given below are some examples that explains how to find the common factors of given numbers.

**Example 1:**Find the common factors of 6 and 8

**Solution:**

Factors of 6 = 1, 2, 3 and 6

Factors of 8 = 1, 2, 4 and 8

Therefore, the common factors of 6 and 8 = 1 and 2.

It can be observed that each common factor (1 and 2) divide the given numbers 6 and 8 exactly with the remainder = 0.

**Example 2:**

Find the common factors of 8, 12 and 16

**Solution:**

Factors of 8 = 1, 2, 4 and 8

Factors of 12 = 1, 2, 3, 4, 6 and 12

Factors of 16 = 1, 2, 4, 8 and 16

Therefore, common factors of 8, 12 and 16 = 1, 2 and 4.

We observe that each common factor (1, 2 and 4) divides the given numbers 8, 12 and 16 exactly with the remainder = 0.

**Example 3:**

Find the common factors of 14, 21 and 42

**Solution:**

Factors of 14 = 1, 2 and 7

Factors of 21 = 1, 3 and 7

Factors of 42 = 1, 2, 3, 6, 7,14, 21 and 42

Therefore, common factor of 14, 21 and 42 = 1and 7

We can observe that each common factor (1 and 7) divides the given number 14, 21 and 42 exactly with the remainder = 0.