Solution: The LCM of 77 and 65 is 5005
Methods
How to find the LCM of 77 and 65 using Prime Factorization
One way to find the LCM of 77 and 65 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 77?
What are the Factors of 65?
Here is the prime factorization of 77:
7
1
×
1
1
1
7^1 × 11^1
7 1 × 1 1 1
And this is the prime factorization of 65:
5
1
×
1
3
1
5^1 × 13^1
5 1 × 1 3 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: 7, 11, 5, 13
5
1
×
7
1
×
1
1
1
×
1
3
1
=
5005
5^1 × 7^1 × 11^1 × 13^1 = 5005
5 1 × 7 1 × 1 1 1 × 1 3 1 = 5005
Through this we see that the LCM of 77 and 65 is 5005.
How to Find the LCM of 77 and 65 by Listing Common Multiples
The first step to this method of finding the Least Common Multiple of 77 and 65 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, 77 and 65:
What are the Multiples of 77?
What are the Multiples of 65?
Let’s take a look at the first 10 multiples for each of these numbers, 77 and 65:
First 10 Multiples of 77: 77, 154, 231, 308, 385, 462, 539, 616, 693, 770
First 10 Multiples of 65: 65, 130, 195, 260, 325, 390, 455, 520, 585, 650
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 77 and 65 are 5005, 10010, 15015. Because 5005 is the smallest, it is the least common multiple.
The LCM of 77 and 65 is 5005.
Find the LCM of Other Number Pairs
Want more practice? Try some of these other LCM problems:
What is the LCM of 62 and 24?
What is the LCM of 99 and 28?
What is the LCM of 56 and 38?
What is the LCM of 133 and 6?
What is the LCM of 123 and 17?