Solution: The GCF of 61 and 124 is 1
Methods
How to find the GCF of 61 and 124 using Prime Factorization
One way to find the GCF of 61 and 124 is to compare 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 61?
What are the Factors of 124?
Here is the prime factorization of 61:
6
1
1
61^1
6 1 1
And this is the prime factorization of 124:
2
2
×
3
1
1
2^2 × 31^1
2 2 × 3 1 1
When you compare the prime factorization of these two numbers, you can see that there are no matching prime factors. When this is the case, it means that there are no common factors between these two numbers. As a result, the GCF of 61 and 124 is 1.
Thus, the GCF of 61 and 124 is: 1
How to Find the GCF of 61 and 124 by Listing All Common Factors
The first step to this method of finding the Greatest Common Factor of 61 and 124 is to find and list all the factors of each number. Again, you can see how this is done by looking at the “Factors of” articles that are linked to above.
Let’s take a look at the factors for each of these numbers, 61 and 124:
Factors of 61: 1, 61
Factors of 124: 1, 2, 4, 31, 62, 124
When you compare the two lists of factors, you can see that the only common factor is 1. So, in this case, the GCF of 61 and 124 is 1.
Find the GCF of Other Number Pairs
Want more practice? Try some of these other GCF problems:
What is the GCF of 26 and 92?
What is the GCF of 124 and 101?
What is the GCF of 38 and 40?
What is the GCF of 127 and 133?
What is the GCF of 18 and 7?