# What is the HCF of 210 and 55?

HCF of 210 and 55 is the greatest number which divides both 210 and 55 without leaving any remainder.

## Answer: HCF of 210 and 55 is 5

Let's find the HCF of 12 and 18

## Explanation:

We can find the HCF by the following methods

### Method 1: HCF of 210 and 55 by listing the factors

Let us list all the factors of 55 and 210 and identify the common factors. the biggest number among all the common factors of 210 and 55 is the HCF of 210 and 55

Factors of 210: 1, 2, 3, 5, 6, 7, 10, 14, 15, 21, 30, 35, 42, 70, 105 and 210

Factors of 55:1, 5, 11 and 55

Common factors of 210 and 55: {1, 5}

Highest among the common factors of 210 and 55 is 5.

Therefore HCF(210,55) is 5.

### Method 2: HCF of 210 and 55 by long division

divide 210 by 55 and check the remainder.

Now, make the remainder 45 the divisor and the divisor of the above step 55 as the dividend and perform the long division till you get 0.

The last divisor 5 is the HCF of 210 and 55