LCM of 5 and 7 is 35. The lowest common multiple of any two or more natural numbers is the number that is the lowest of their common multiples. We can find the LCM of 5 and 7 by prime factorisation, by division method and by listing multiples. Students can learn how to find the LCM by prime factorisation and division method in a precise manner by following Prime Factorisation and Division Method for LCM and HCF as per their needs. Learn how to find the least common multiple of 5 and 7 using a simple technique in this article.
What is LCM of 5 and 7?
The answer to this question is 35.
How to Find LCM of 5 and 7?
We can determine the LCM of 5 and 7 by using the methods given below:
- Prime Factorisation
- Division method
- Listing the multiples
LCM of 5 and 7 Using Prime Factorisation Method
We can determine the least common multiple of 5 and 7 using prime factorisation method by multiplying prime factors raised to their respective highest power.
5 = 5
7 = 7
LCM (5, 7) = 5 × 7 = 35
LCM of 5 and 7 Using Division Method
To calculate the LCM of 5 and 7 by division method, we divide the numbers 5 and 7 by their prime factors. The product of these divisors represents the least common multiple of 5 and 7.
|
5 |
5 |
7 |
|
7 |
1 |
7 |
|
x |
1 |
1 |
No more further division can be done.
Hence, LCM (5, 7) = 5 × 7 = 35
LCM of 5 and 7 Using Listing the Multiples
By listing out the multiples of 5 and 7, we can find the least common multiple of 5 and 7 with ease.
|
Multiples of 5 |
Multiples of 7 |
|
5 |
7 |
|
10 |
14 |
|
15 |
21 |
|
20 |
28 |
|
25 |
35 |
|
30 |
42 |
|
35 |
49 |
|
40 |
56 |
LCM (5, 7) = 35
Related Articles
Video Lesson on Applications of LCM
Solved Examples
Q.1: Find the LCM of 5 and 7 using the prime factorisation method.
Solution:
5 = 5
7 = 7
LCM of (5, 7) = 5 × 7 = 35
Hence the LCM of 5 and 7 is 35.
Q.2: The GCD and LCM of the two numbers are 1 and 35. If one number is 7. Determine the other number.
Solution: Let the other number be p
GCD × LCM = 7 × m
m = (GCD × LCM)/7
m = (1 × 35)/7
m = 5
Thus the other number is 5.
Frequently Asked Questions on LCM of 5 and 7
What is the LCM of 5 and 7?
How to find the LCM of 5 and 7 by listing multiples?
First write the multiples of 5 and 7
Multiples of 5 = 5, 10, 15, 20, 25, 30, 35, 40…
Multiples of 7 = 7, 14, 21, 28, 35, 42, 49…
The LCM of (5, 7) = 35
Therefore the least common multiple of 5 and 7 is 35.
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