GCF of 84/42, 81/21, 77/70, 20/98
Reviewed By : Phani Ponnapalli
Last Updated at : Mar 29,2023
Use our free GCF of Fractions Calculator tool to compute the GCF of 84/42, 81/21, 77/70, 20/98 i.e 1/1470 easily. The following is the detailed procedure to determine the greatest common factor of fractions 84/42, 81/21, 77/70, 20/98.
Enter two or more fractions separated by "commas"
Ex: 2/3, 5/7 or 3/5, 5/9, 7/3
What is the GCF of 84/42,81/21,77/70,20/98?
Given fractions are 84/42,81/21,77/70,20/98
To find the GCF of fractions, we have to find the GCF of numerator numbers and LCM of denominator numbers. Its formula is given by
GCF of Fraction = Greatest Common Factor of Numerator/Least Common Multiple of Denominators
In the fractions 84/42,81/21,77/70,20/98, numerators are 84,81,77,20
Denominators are 42,21,70,98
The GCF of 84,81,77,20 is 1 .
LCM of 42,21,70,98 is 1470.
The greatest common factor of 84/42,81/21,77/70,20/98 = [GCF of 84,81,77,20]/[LCM of 42,21,70,98]= 1/1470
Therefore, the GCF of 84/42,81/21,77/70,20/98 is 1/1470.
To find the highest common factor of 84,81,77,20, we have to find the factors of both numbers and list the highest common factor.
The factors of 84 are 1, 2, 3, 4, 6, 7, 12, 14, 21, 28, 42, 84
The factors of 81 are 1, 3, 9, 27, 81
The factors of 77 are 1, 7, 11, 77
The factors of 20 are 1, 2, 4, 5, 10, 20
The HCF of 84,81,77,20 is 1.
Lets's calculate GCF of 84,81,77,20
∴ So GCF of numbers is 1 because of no common factors present between them.
Greatest Common Factor of 84,81,77,20 By Matching Biggest Common Factor Method
Now, list down the factors of 84
:1,2,3,4,6,7,12,14,21,28,42,84
Now, list down the factors of 81
:1,3,9,27,81
Now, list down the factors of 77
:1,7,11,77
Now, list down the factors of 20
:1,2,4,5,10,20
Greatest Common Factor
We found the factors 84,81,77,20 . The biggest common factor number is the GCF number.
So the greatest common factor 84,81,77,20 is 1.
Lets's calculate LCM of 42,21,70,98
| 2 | 42, 21, 70, 98 |
| 3 | 21, 21, 35, 49 |
| 7 | 7, 7, 35, 49 |
| 1, 1, 5, 7 |
∴ So the LCM of the given numbers is 2 x 3 x 7 x 1 x 1 x 5 x 7 = 1470
Thus GCF of Fractions = GCF of Numerators/LCM of Denominators = 1/1470
Therefore, the GCF of Fractions 84/42,81/21,77/70,20/98 is 1/1470
Least Common Multiple of 42,21,70,98 with GCF Formula
The formula of LCM is LCM(a1,a2,a3....,an) = ( a1 × a2 × a3 × .... × an) / GCF(a1,a2,a3....,an) x common factors(if more than 2 numbers have common factors).
We need to calculate greatest common factor of 42,21,70,98 and common factors if more than two numbers have common factor, than apply into the LCM equation.
GCF(42,21,70,98) = 7
common factors(in case of two or more numbers have common factors) = 588
GCF(42,21,70,98) x common factors =7 x 588 = 4116
LCM(42,21,70,98) = ( 42 × 21 × 70 × 98 ) / 4116
LCM(42,21,70,98) = 6050520 / 4116
LCM(42,21,70,98) = 1470
GCF of Fractions Calculation Examples
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FAQs on GCF of Fractions of 84/42, 81/21, 77/70, 20/98
1. What is the HCF of 84,81,77,20?
The HCF of 84,81,77,20 is 1
2. What is the GCF of a fraction?
The GCF of a fraction is defined as the greatest fraction that divides exactly into 2 or more fractions.
3. How to find GCF in Fractions?
Answer: GCF of fractions can be found using the simple formula GCF of Fractions = GCF of Numerators/LCM of Denominators.
4. What is the GCF of Fractions for 84/42, 81/21, 77/70, 20/98?
Answer: GCF of Numerators as per given numbers 84/42, 81/21, 77/70, 20/98 is
GCF of Numerators i.e. for 84,81,77,20 is 1
LCM of denominators i.e. for 42,21,70,98 is 1470.
Thus, GCF of Fractions is 1/1470.Finally, GCF of Fractions for 84/42, 81/21, 77/70, 20/98 is 1/1470.