Created By : Jatin Gogia
Reviewed By : Rajasekhar Valipishetty
Last Updated : Apr 06, 2023
Make use of GCF Calculator to quickly find the Greatest Common Factor of numbers 75, 81 i.e. 3 largest integer by which both the numbers can be divided.
Greatest common factor (GCF) of 75 and 81 is 3.
GCF(75,81) = 3
Greatest common factor or Greatest common divisor (GCD) can be calculated in following way;
Prime Factorization of 75
3 | 75 |
5 | 25 |
5 | 5 |
1 |
Prime factors of 75 are 3,5. Prime factorization of 75 in exponential form is:
75 = 31×52
Prime Factorization of 81
3 | 81 |
3 | 27 |
3 | 9 |
3 | 3 |
1 |
Prime factors of 81 are 3. Prime factorization of 81 in exponential form is:
81 = 34
∴ So by taking common prime factors GCF of 75 and 81 is 3
Factors of 75
List of positive integer factors of 75 that divides 75 without a remainder.
1,3,5,15,25,75
Factors of 81
List of positive integer factors of 81 that divides 81 without a remainder.
1,3,9,27,81
Greatest Common Factor
We found the factors and prime factorization of 75 and 81. The biggest common factor number is the GCF number.
So the greatest common factor 75 and 81 is 3.
Also check out the Least Common Multiple of 75 and 81
(i) The GCF of 75 and 81 is associative
GCF of 75 and 81 = GCF of 81 and 75
1. What is the GCF of 75 and 81?
Answer: GCF of 75 and 81 is 3.
2. What are the Factors of 75?
Answer: Factors of 75 are 1, 3, 5, 15, 25, 75. There are 6 integers that are factors of 75. The greatest factor of 75 is 75.
3. What are the Factors of 81?
Answer: Factors of 81 are 1, 3, 9, 27, 81. There are 5 integers that are factors of 81. The greatest factor of 81 is 81.
4. How to Find the GCF of 75 and 81?
Answer:
Greatest Common Factor of 75 and 81 = 3
Step 1: Find the prime factorization of 75
75 = 3 x 5 x 5
Step 2: Find the prime factorization of 81
81 = 3 x 3 x 3 x 3
Step 3: Multiply those factors both numbers have in common in steps i) or ii) above to find the gcf:
GCF = 3
Step 4: Therefore, the greatest common factor of 75 and 81 is 3