Solution: The LCM of 105 and 54 is 1890
Methods
How to find the LCM of 105 and 54 using Prime Factorization
One way to find the LCM of 105 and 54 is to start by comparing the prime factorization of each number. To find the prime factorization, you can follow the instructions for each number here:
What are the Factors of 105?
What are the Factors of 54?
Here is the prime factorization of 105:
3
1
×
5
1
×
7
1
3^1 × 5^1 × 7^1
3 1 × 5 1 × 7 1
And this is the prime factorization of 54:
2
1
×
3
3
2^1 × 3^3
2 1 × 3 3
When you compare the prime factorization of these two numbers, you want to look for the highest power that each prime factor is raised to. In this case, there are these prime factors to consider: 3, 5, 7, 2
2
1
×
3
3
×
5
1
×
7
1
=
1890
2^1 × 3^3 × 5^1 × 7^1 = 1890
2 1 × 3 3 × 5 1 × 7 1 = 1890
Through this we see that the LCM of 105 and 54 is 1890.
How to Find the LCM of 105 and 54 by Listing Common Multiples
The first step to this method of finding the Least Common Multiple of 105 and 54 is to begin to list a few multiples for each number. If you need a refresher on how to find the multiples of these numbers, you can see the walkthroughs in the links below for each number.
Let’s take a look at the multiples for each of these numbers, 105 and 54:
What are the Multiples of 105?
What are the Multiples of 54?
Let’s take a look at the first 10 multiples for each of these numbers, 105 and 54:
First 10 Multiples of 105: 105, 210, 315, 420, 525, 630, 735, 840, 945, 1050
First 10 Multiples of 54: 54, 108, 162, 216, 270, 324, 378, 432, 486, 540
You can continue to list out the multiples of these numbers as long as needed to find a match. Once you do find a match, or several matches, the smallest of these matches would be the Least Common Multiple. For instance, the first matching multiple(s) of 105 and 54 are 1890, 3780, 5670. Because 1890 is the smallest, it is the least common multiple.
The LCM of 105 and 54 is 1890.
Find the LCM of Other Number Pairs
Want more practice? Try some of these other LCM problems:
What is the LCM of 73 and 95?
What is the LCM of 98 and 45?
What is the LCM of 27 and 52?
What is the LCM of 37 and 127?
What is the LCM of 86 and 46?