Solution: The LCM of 11 and 28 is 308
Methods
How to find the LCM of 11 and 28 using Prime Factorization
One way to find the LCM of 11 and 28 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 11?
What are the Factors of 28?
Here is the prime factorization of 11:
1
1
1
11^1
1 1 1
And this is the prime factorization of 28:
2
2
×
7
1
2^2 × 7^1
2 2 × 7 1
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: 11, 2, 7
2
2
×
7
1
×
1
1
1
=
308
2^2 × 7^1 × 11^1 = 308
2 2 × 7 1 × 1 1 1 = 308
Through this we see that the LCM of 11 and 28 is 308.
How to Find the LCM of 11 and 28 by Listing Common Multiples
The first step to this method of finding the Least Common Multiple of 11 and 28 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, 11 and 28:
What are the Multiples of 11?
What are the Multiples of 28?
Let’s take a look at the first 10 multiples for each of these numbers, 11 and 28:
First 10 Multiples of 11: 11, 22, 33, 44, 55, 66, 77, 88, 99, 110
First 10 Multiples of 28: 28, 56, 84, 112, 140, 168, 196, 224, 252, 280
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 11 and 28 are 308, 616, 924. Because 308 is the smallest, it is the least common multiple.
The LCM of 11 and 28 is 308.
Find the LCM of Other Number Pairs
Want more practice? Try some of these other LCM problems:
What is the LCM of 91 and 47?
What is the LCM of 37 and 133?
What is the LCM of 14 and 50?
What is the LCM of 129 and 141?
What is the LCM of 15 and 134?