Highest Common Factor of 42, 90, 20 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, 90, 20 i.e. 2 the largest integer that leaves a remainder zero for all numbers.

HCF of 42, 90, 20 is 2 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, 90, 20 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, 90, 20 is 2.

HCF(42, 90, 20) = 2

HCF of 42, 90, 20 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, 90, 20 is 2.

Highest Common Factor of 42,90,20 using Euclid's algorithm

Highest Common Factor of 42,90,20 is 2

Step 1: Since 90 > 42, we apply the division lemma to 90 and 42, to get

90 = 42 x 2 + 6

Step 2: Since the reminder 42 ≠ 0, we apply division lemma to 6 and 42, to get

42 = 6 x 7 + 0

The remainder has now become zero, so our procedure stops. Since the divisor at this stage is 6, the HCF of 42 and 90 is 6

Notice that 6 = HCF(42,6) = HCF(90,42) .


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

Step 1: Since 20 > 6, we apply the division lemma to 20 and 6, to get

20 = 6 x 3 + 2

Step 2: Since the reminder 6 ≠ 0, we apply division lemma to 2 and 6, to get

6 = 2 x 3 + 0

The remainder has now become zero, so our procedure stops. Since the divisor at this stage is 2, the HCF of 6 and 20 is 2

Notice that 2 = HCF(6,2) = HCF(20,6) .

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Frequently Asked Questions on HCF of 42, 90, 20 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, 90, 20?

Answer: HCF of 42, 90, 20 is 2 the largest number that divides all the numbers leaving a remainder zero.

3. How to find HCF of 42, 90, 20 using Euclid's Algorithm?

Answer: For arbitrary numbers 42, 90, 20 apply Euclid’s Division Lemma in succession until you obtain a remainder zero. HCF is the remainder in the last but one step.