Highest Common Factor of 42, 21, 84, 42 using Euclid's algorithm

Created By : Jatin Gogia

Reviewed By : Rajasekhar Valipishetty

Last Updated : Apr 06, 2023


HCF Calculator using the Euclid Division Algorithm helps you to find the Highest common factor (HCF) easily for 42, 21, 84, 42 i.e. 21 the largest integer that leaves a remainder zero for all numbers.

HCF of 42, 21, 84, 42 is 21 the largest number which exactly divides all the numbers i.e. where the remainder is zero. Let us get into the working of this example.

Consider we have numbers 42, 21, 84, 42 and we need to find the HCF of these numbers. To do so, we need to choose the largest integer first and then as per Euclid's Division Lemma a = bq + r where 0 ≤ r ≤ b

Highest common factor (HCF) of 42, 21, 84, 42 is 21.

HCF(42, 21, 84, 42) = 21

HCF of 42, 21, 84, 42 using Euclid's algorithm

Highest common factor or Highest common divisor (hcd) can be calculated by Euclid's algotithm.

HCF of:

Highest common factor (HCF) of 42, 21, 84, 42 is 21.

Highest Common Factor of 42,21,84,42 using Euclid's algorithm

Highest Common Factor of 42,21,84,42 is 21

Step 1: Since 42 > 21, we apply the division lemma to 42 and 21, to get

42 = 21 x 2 + 0

The remainder has now become zero, so our procedure stops. Since the divisor at this stage is 21, the HCF of 42 and 21 is 21

Notice that 21 = HCF(42,21) .


We can take hcf of as 1st numbers and next number as another number to apply in Euclidean lemma

Step 1: Since 84 > 21, we apply the division lemma to 84 and 21, to get

84 = 21 x 4 + 0

The remainder has now become zero, so our procedure stops. Since the divisor at this stage is 21, the HCF of 21 and 84 is 21

Notice that 21 = HCF(84,21) .


We can take hcf of as 1st numbers and next number as another number to apply in Euclidean lemma

Step 1: Since 42 > 21, we apply the division lemma to 42 and 21, to get

42 = 21 x 2 + 0

The remainder has now become zero, so our procedure stops. Since the divisor at this stage is 21, the HCF of 21 and 42 is 21

Notice that 21 = HCF(42,21) .

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Frequently Asked Questions on HCF of 42, 21, 84, 42 using Euclid's Algorithm

1. What is the Euclid division algorithm?

Answer: Euclid's Division Algorithm is a technique to compute the Highest Common Factor (HCF) of given positive integers.

2. what is the HCF of 42, 21, 84, 42?

Answer: HCF of 42, 21, 84, 42 is 21 the largest number that divides all the numbers leaving a remainder zero.

3. How to find HCF of 42, 21, 84, 42 using Euclid's Algorithm?

Answer: For arbitrary numbers 42, 21, 84, 42 apply Euclid’s Division Lemma in succession until you obtain a remainder zero. HCF is the remainder in the last but one step.