Banner 0
Banner 1
Banner 2
Banner 3
Banner 4
Banner 5
Banner 6
Banner 7
Banner 8
Banner 9

Q.

The Co-primes from the following pairs are ____.


see full answer

Your Exam Success, Personally Taken Care Of

1:1 expert mentors customize learning to your strength and weaknesses – so you score higher in school , IIT JEE and NEET entrance exams.
An Intiative by Sri Chaitanya

(Unlock A.I Detailed Solution for FREE)

Best Courses for You

JEE

JEE

NEET

NEET

Foundation JEE

Foundation JEE

Foundation NEET

Foundation NEET

CBSE

CBSE

Detailed Solution

We are asked to find the pair which are co – primes from the given pairs.
Let us check each and every Options one by one.
(1) 7 and 63
Now, let us use the prime factorisation for the number 7
Here, we can see that the number 7 is a prime number
So, we can take the prime factorisation for 7 as
⇒7=1×7
Now, let us use the prime factorisation method for 63 then we get
63= 3 2 ×7  
Here, we can see that there is common prime 7 in the prime factorisation of 7 and 63
We know that the co – primes are the pair of numbers having only one common factor that is 1
By using the above condition we can conclude that the pair 7 and 63 are not co – primes.
(2) 36 and 25
Now, let us use the prime factorisation method for 36 then we get
36= 2 2 × 3 2  
Now, let us use the prime factorisation method for 25 then we get
25= 5 2  
Here, we can see that there are no common factors for 36 and 25
By using the co – primes definition we can conclude that the pair 36 and 25 are co – primes.
(3) 35 and 21
Now, let us use the prime factorisation method for 35 then we get
⇒35=5×7
Now, let us use the prime factorisation method for 21 then we get
⇒21=3×7
Here, we can see that there is common factor for 35 and 21 that is 7
By using the co – primes definition we can conclude that the pair 35 and 21 are not co – primes.
(4) 63 and 81
Now, let us use the prime factorization method for 63 then we get
63= 3 2 ×7  
Now, let us use the prime factorization method for 81 then we get
81= 3 4  
Here, we can see that there are no common factors for 63 and 81 that is 3
By using the co – primes definition we can conclude that the pair 63 and 81 are not co – primes.
 
Watch 3-min video & get full concept clarity
score_test_img

courses

No courses found

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Get Expert Academic Guidance – Connect with a Counselor Today!

best study material, now at your finger tips!

  • promsvg

    live classes

  • promsvg

    progress tracking

  • promsvg

    24x7 mentored guidance

  • promsvg

    study plan analysis

download the app

gplay
mentor

Download the App

gplay
whats app icon
personalised 1:1 online tutoring