HCF of 8 and 20

The HCF of 8 and 20 is 4. The numbers 8 and 20 are divisible by the highest integer, which is the HCF. The factors of 8 are 1, 2, 4, 8, and the factors of 20 are 1, 2, 4, 5, 10, 20. The methods to find the HCF are prime factorisation, long division and listing common factors. This article is designed to help students understand the HCF-related concepts with ease.

Also read: Highest common factor

What is the HCF of 8 and 20?

The answer to this question is 4. The HCF of 8 and 20 found with three different methods are explained in-depth here. The value which divides 8 and 20 is the HCF.

How to Find HCF of 8 and 20?

The three methods to get the HCF of 8 and 20 is:

• Prime Factorisation
• Long Division method
• Listing common factors

HCF of 8 and 20 by Prime Factorisation Method

The prime factorisation of 8 and 20 is given by:

8 = 2 × 2 × 2

20 = 2 × 2 × 5

The common prime factors of 8 and 20 = 2, 2

Therefore, HCF (8, 20) = 2 × 2 = 4

HCF of 8 and 20 by Long Division Method

Divide 8 and 20 using the prime factors to get the HCF of 8 and 20. The divisor, when the remainder value is zero, is the HCF of 8 and 20.

No further division can be done.

Hence, HCF (8, 20) = 4

HCF of 8 and 20 by Listing Common Factors

The HCF of 8 and 20 found by listing common factors is given below:

Factors of 8: 1, 2, 4, 8

Factors of 20: 1, 2, 4, 5, 10, 20

There are 3 common factors of 8 and 20, and they are 1, 2 and 4.

Therefore, the highest common factor of 8 and 20 is 4.

Related Articles

• HCF of Two Numbers
• HCF and LCM
• Relation between HCF and LCM
• GCF calculator
• GCF

Video Lesson on Properties of HCF and LCM

HCF of 8 and 20 Solved Example

Question: Determine the HCF of 8 and 20 if the LCM is 40.

Solution:

We know that

LCM × HCF = 8 × 20

HCF = (8 × 20)/40

HCF = 4

Hence, the HCF is 4.