GCD of 21, 77, 90, 42 Calculator
Reviewed By : Phani Ponnapalli
Last Updated at : Mar 29,2023
Online GCD Calculator is useful to find the GCD of 21, 77, 90, 42 quickly. Get the easiest ways to solve the greatest common divisor of 21, 77, 90, 42 i.e 1 in different methods as follows.
Given Input numbers are 21, 77, 90, 42
In the factoring method, we have to find the divisors of all numbers
Divisors of 21 :
The positive integer divisors of 21 that completely divides 21 are.
1, 3, 7, 21
Divisors of 77 :
The positive integer divisors of 77 that completely divides 77 are.
1, 7, 11, 77
Divisors of 90 :
The positive integer divisors of 90 that completely divides 90 are.
1, 2, 3, 5, 6, 9, 10, 15, 18, 30, 45, 90
Divisors of 42 :
The positive integer divisors of 42 that completely divides 42 are.
1, 2, 3, 6, 7, 14, 21, 42
GCD of numbers is the greatest common divisor
So, the GCD (21, 77, 90, 42) = 1.
Given numbers are 21, 77, 90, 42
The list of prime factors of all numbers are
Prime factors of 21 are 3 x 7
Prime factors of 77 are 7 x 11
Prime factors of 90 are 2 x 3 x 3 x 5
Prime factors of 42 are 2 x 3 x 7
The above numbers do not have any common prime factor. So GCD is 1
Steps to Calculate GCD of 21, 77, 90, 42 using LCM Formula
Given numbers are 21, 77, 90, 42
GCD of 2 numbers formula is GCD(a, b) = ( a x b) / LCM(a, b)
Apply this formula for all numbers.
Step1:
LCM(21, 77) = 231
GCD(21, 77) = ( 21 x 77 ) / 231
= 21 / 77
= 21
Step2:
LCM(7, 90) = 630
GCD(7, 90) = ( 7 x 90 ) / 630
= 7 / 90
= 7
Step3:
LCM(1, 42) = 42
GCD(1, 42) = ( 1 x 42 ) / 42
= 1 / 42
= 1
So, Greatest Common Divisor of 21, 77, 90, 42 is 1
GCD of Numbers Calculation Examples
Here are some samples of GCD of Numbers calculations.
Greatest Common Divisor of 21, 77, 90, 42
Given numbers are 21, 77, 90, 42
The greatest common divisor of numbers 21, 77, 90, 42 can be found in various methods such as the LCM formula, factoring, and prime factorization. The GCD of numbers 21, 77, 90, 42 is 1.
FAQs on GCD of 21, 77, 90, 42 Calculator
1. What is the GCD of 21, 77, 90, 42?
GCD of given numbers 21, 77, 90, 42 is 1
2. How to calculate the greatest common divisor of 21, 77, 90, 42?
We can find the highest common divisor of 21, 77, 90, 42 easily using the prime factorization method. Just list the prime factors of all numbers and pick the highest common factor which is the GCD of 21, 77, 90, 42 i.e 1.
3. How can I use the GCD of 21, 77, 90, 42Calculator?
Out the numbers 21, 77, 90, 42 into the GCD calculator and hit the calculate button to get the greatest common divisor as result.