Solution: The GCF of 48 and 72 is 24
Methods
How to find the GCF of 48 and 72 using Prime Factorization
One way to find the GCF of 48 and 72 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 48?
What are the Factors of 72?
Here is the prime factorization of 48:
2
4
×
3
1
2^4 × 3^1
2 4 × 3 1
And this is the prime factorization of 72:
2
3
×
3
2
2^3 × 3^2
2 3 × 3 2
When you compare the prime factorization of these two numbers, you can see that there are matching prime factors. You can now find the Greatest Common Factor of 48 and 72 by multiplying all the matching prime factors to get a GCF of 48 and 72 as 36:
Thus, the GCF of 48 and 72 is: 36
How to Find the GCF of 48 and 72 by Listing All Common Factors
The first step to this method of finding the Greatest Common Factor of 48 and 72 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, 48 and 72:
Factors of 48: 1, 2, 3, 4, 6, 8, 12, 16, 24, 48
Factors of 72: 1, 2, 3, 4, 6, 8, 9, 12, 18, 24, 36, 72
When you compare the two lists of factors, you can see that the common factor(s) are 1, 2, 3, 4, 6, 8, 12, 24. Since 24 is the largest of these common factors, the GCF of 48 and 72 would be 24.
Find the GCF of Other Number Pairs
Want more practice? Try some of these other GCF problems:
What is the GCF of 124 and 39?
What is the GCF of 83 and 41?
What is the GCF of 51 and 134?
What is the GCF of 145 and 70?
What is the GCF of 4 and 107?