The HCF of 18 and 45 is 9. The numbers 18 and 45 can be divided evenly by the HCF value. The factors of 18 are 1, 2, 3, 6, 9, and 18, and the factors of 45 are 1, 3, 5, 9, 15, and 45. The methods used in the calculation of HCF value are long division, prime factorisation and listing common factors. The articles at BYJU’S are curated with care by the faculty who wish to provide quality materials for the students’ reference.
Also read: Highest common factor
What is the HCF of 18 and 45?
The answer to this question is 9. The three methods used to find the HCF of 18 and 45 are sharply outlined here. The largest number which divides 18 and 45 evenly denotes the HCF of 18 and 45.
How to Find the HCF of 18 and 45?
The methods to find the HCF of 18 and 45 are :
- Prime Factorisation
- Long Division method
- Listing common factors
HCF of 18 and 45 by Prime Factorisation Method
The prime factorisation of 18 and 45 is:
18 = 2 × 3 × 3
45 = 3 × 3 × 5
The common prime factors of 18 and 45 are 3, 3
Hence, HCF (18, 45) = 3 × 3 = 9
HCF of 18 and 45 by Long Division Method
The numbers (18, 45) should be divided by the factors to find the HCF of 18 and 45. The value of the divisor when the remainder is zero is the HCF of 18 and 45.
No further division can be done.
Hence, HCF (18, 45) = 9
HCF of 18 and 45 by Listing Common Factors
The HCF of 18 and 45 by listing common factors is:
Factors of 18: 1, 2, 3, 6, 9, 18
Factors of 45: 1, 3, 5, 9, 15, 45
There are 3 common factors of 18 and 45, and they are 1, 3 and 9.
Therefore, the highest common factor of 18 and 45 is 9.
Related Articles
- Prime Factorization Calculator
- Properties of HCF and LCM
- Prime Factorisation and Division Method for HCF and LCM
- Prime Factorisation
- GCD Calculator
Video Lesson on Properties of HCF and LCM
![](https://cdn1.byjus.com/wp-content/uploads/2022/05/Properties-of-HCF-and-LCM.jpg)
HCF of 18 and 45 Solved Example
Question: If the product of two numbers = 810 and HCF = 9, find the LCM.
Solution:
Given
Product of two numbers = 810
HCF = 9
HCF × LCM = Product of two numbers
9 × LCM = 486
LCM = 810/9
LCM = 90
Hence, the LCM is 90.
Frequently Asked Questions on HCF of 18 and 45
Calculate the HCF of 18 and 45 if the LCM is 90.
Given
LCM = 90
LCM × HCF = 18 × 45
HCF = (18 × 45)/ 90
HCF = 9
Calculate the HCF of 18 and 45 using the long division method.
Write the methods used to find HCF of 18 and 45.
What is the HCF of 18 and 45?
What is the relation between HCF and LCM of 18 and 45?
The relation between HCF and LCM of 18 and 45 is
HCF × LCM = 18 × 45
HCF × LCM = 810
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