LCM of 5 and 18 is 90. LCM denotes the smallest positive number that is a multiple of two or more numbers. Subject matter experts crafted the article LCM with Examples to help students attain optimum marks in final examinations. Students can make use of this article for better understanding when they get stuck while solving complex problems. Learn the detailed explanation of how to verify the least common multiple of 5 and 18 with suitable examples in this article.
What is LCM of 5 and 18?
The Least Common Multiple of 5 and 18 is 90.
How to Find LCM of 5 and 18?
LCM of 5 and 18 can be determined using three methods:
- Prime Factorisation
- Division method
- Listing the Multiples
LCM of 5 and 18 Using Prime Factorisation Method
In the prime factorisation method, LCM of 5 and 18 can be obtained by multiplying prime factors raised to their respective highest power.
5 = 5
18 = 2 × 3 × 3
LCM (5, 18) = 2 × 3 × 3 × 5 = 90
LCM of 5 and 18 Using Division Method
In the division method, to find the LCM, we divide the numbers 5 and 18 by their prime factors until we get the result as one in the complete row. The product of these divisors shows the least common multiple of 5 and 18.
| 2 | 5 | 18 |
| 3 | 5 | 9 |
| 3 | 5 | 3 |
| 5 | 5 | 1 |
| x | 1 | 1 |
No further division can be done.
Hence, LCM (5, 18) = 2 × 3 × 3 × 5 = 90
LCM of 5 and 18 Using Listing the Multiples
In this method, we list down the multiples of given natural numbers to determine the least common multiple among them. Let us have a look at the multiples of 5 and 18 here.
Multiples of 5: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90,…………
Multiples of 18: 18, 36, 54, 72, 90, 108, 126, 144, 162, 180………….
LCM (5, 18) = 90
Related Articles
Prime Factorisation and Division Method for LCM and HCF
Video Lesson on Applications of LCM
Solved Examples
1. What is the smallest number that is divisible by both 5 and 18?
Solution: 90 is the smallest number that is divisible by both 5 and 18.
2. What is the LCM if the product of two numbers is 90 and their GCD is 1?
Solution: Given,
GCD = 1
Product of numbers = 90
We know that
GCD × LCM = Product of numbers
LCM = Product of numbers/GCD
LCM = 90/1
LCM = 90
Therefore the LCM is 90.
Frequently Asked Questions on LCM of 5 and 18
What is the LCM of 5 and 18?
What are the methods used to find the least common multiple of 5 and 18?
The methods used to find the least common multiple of 5 and 18 are:
Prime Factorisation
Division method
Listing the Multiples
Is 80 the LCM of 5 and 18?
What is the LCM of 5 and 18 and the HCF of 5 and 18?
Find the GCF if the LCM of 5 and 18 is 90.
GCF × LCM = 5 × 18
Given
LCM = 90
GCF × 90 = 5 × 18
GCF = 1
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