arrow
arrow
arrow
Which of the following is a pair of co-prime numbers?
Question

Which of the following is a pair of co-prime numbers?

A.

455,49

B.

81,16

C.

363,77

D.

52,24

Correct option is B

Solution:

Two numbers are said to be co-prime if their greatest common divisor (GCD) is 1, i.e., they do not have any common factor other than 1.

Let's check the GCD of each pair:

A) 455, 49

- HCF of 455 and 49 is 7, so 455 and 49 are not co-prime.

2. B) 81, 16

- HCF of 81 and 16 is 1, so 81 and 16 are co-prime.

3. C) 363, 77

- HCF of 363 and 77 is 11, so 363 and 77 are not co-prime.

4. D) 52, 24

- HCF of 52 and 24 is 4, so 52 and 24 are not co-prime.

Thus, the pair of co-prime numbers is 81 and 16.

Free Tests

Free
Must Attempt

RRB NTPC UG Level PYP (Held on 7 Aug 2025 S1)

languageIcon English
  • pdpQsnIcon100 Questions
  • pdpsheetsIcon100 Marks
  • timerIcon90 Mins
languageIcon English
Free
Must Attempt

CBT-1 Full Mock Test 1

languageIcon English
  • pdpQsnIcon100 Questions
  • pdpsheetsIcon100 Marks
  • timerIcon90 Mins
languageIcon English
Free
Must Attempt

RRB Group D Full Mock Test 1

languageIcon English
  • pdpQsnIcon100 Questions
  • pdpsheetsIcon100 Marks
  • timerIcon90 Mins
languageIcon English
test-prime-package

Access ‘RRB Technician Grade 3’ Mock Tests with

  • 60000+ Mocks and Previous Year Papers
  • Unlimited Re-Attempts
  • Personalised Report Card
  • 500% Refund on Final Selection
  • Largest Community
students-icon
446k+ students have already unlocked exclusive benefits with Test Prime!
Our Plans
Monthsup-arrow