The HCF of 20, 25 and 30 is 5. The largest factor of two or more numbers is defined as the Highest Common Factor of 20, 25 and 30. The article HCF help students to obtain proficiency in solving problems relying on Highest Common Factor. Following this article also boosts confidence among students, which is essential from an exam perspective. Let us learn the simple method to determine the Highest Common Factor of 20, 25 and 30 with the help of solved examples and FAQs in this article.
What is the HCF of 20, 25 and 30?
The Highest Common Factor (HCF) of 20, 25 and 30 is 5. The factors of 20 are 1, 2, 4, 5, 10, 20, the factors of 25 are 1, 5, 25 and the factors of 30 are 1, 2, 3, 5, 6, 10, 15, 30 respectively. Among these factors, clearly, 5 is the Highest Common Factor of 20, 25 and 30.
How to Find HCF of 20, 25 and 30?
Let us glance at the methods used to find the HCF of 20, 25 and 30:
- Prime Factorisation
- Long Division method
- Listing common factors
HCF of 20, 25 and 30 by Prime Factorisation Method
In the prime factorisation, we write the numbers as the product of prime factors to find their HCF. Hence, the numbers 20, 25 and 30 are expressed as:
20 = 2 × 2 × 5
25 = 5 × 5
30 = 2 × 3 × 5
Common prime factor of 20, 25 and 30 is 5
Therefore,
HCF (20, 25, 30) = 5
HCF of 20, 25 and 30 by Long Division Method
Follow the steps given below to find the Highest Common Factor of 20, 25 and 30 using the long division method.
Step 1: Divide the largest number 30 by the smallest number 20.
Step 2: We get the divisor as 10 when the remainder is equal to zero. Hence, the HCF of 20 and 30 is 10.
Step 3: Now, we perform the long division process on 10 and 25 to find the HCF. We get the divisor as 5 when the remainder is zero. Therefore, the HCF of 10 and 25 is 5.
The HCF of 20, 25 and 30 by the long division method is shown below;
First, calculate the HCF of 20 and 30
HCF of 20 and 30 is 10 and the HCF of 10 and 25 is 5
Hence, the HCF (20, 25, 30) = 5
HCF of 20, 25 and 30 by Listing the Factors
In this method, list out the factors of given numbers and choose the highest of all the common prime factors, as mentioned below:
Factors of 20: 1, 2, 4, 5, 10, 20
Factors of 25: 1, 5, 25
Factors of 30: 1, 2, 3, 5, 6, 10, 15, 30
Therefore, HCF (20, 25, 30) = 5
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Solved Example
Question: What is the highest number that divides 20, 25 and 30 completely?
Solution: The largest number that divides 20, 25 and 30 completely is their Highest Common Factor (HCF). The factors of 20, 25 and 30 are as follows:
Factors of 20: 1, 2, 4, 5, 10, 20
Factors of 25: 1, 5, 25
Factors of 30: 1, 2, 3, 5, 6, 10, 15, 30
The Highest Common Factor of 20, 25 and 30 is 5.
Hence, the highest number that divides 20, 25 and 30 completely is 5.
Frequently Asked Questions on HCF of 20, 25 and 30
What is the HCF of 20, 25 and 30?
Name the methods used to find the HCF of 20, 25 and 30.
There are three methods to find the HCF of 20, 25 and 30. They are as follows:
Prime Factorisation
Long Division method
Listing common factors
Is 350 the LCM of 20, 25 and 30?
The HCF of 20, 25 and 30 and the HCF of 25, 30 and 35 are the same. True or False.
Find the HCF of 20, 25 and 30 using prime factorisation.
In the prime factorisation, to find the HCF, we express the given numbers as the product of prime factors
20 = 2 × 2 × 5
25 = 5 × 5
30 = 2 × 3 × 5
Common prime factor of 20, 25 and 30 is 5
Therefore,HCF (20, 25, 30) = 5
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