HCF of two number is 4 and the sum of those two numbers is 36. Find how many such pair of number is possible.

  1. 1
  2. 2
  3. 3
  4. 4

Answer (Detailed Solution Below)

Option 3 : 3
Free
RRB NTPC CBT-I Official Paper (Held On: 4 Jan 2021 Shift 1)
5.5 Lakh Users
100 Questions 100 Marks 90 Mins

Detailed Solution

Download Solution PDF

Given:

HCF of two number is 4 and the sum of those two numbers is 36.

Concept Used:

Concept of HCF

HCF is the least common factor among two or more numbers.

Calculation:

HCF of two number is 4

Let, those numbers be 4x and 4y where x and y are prime to each other

Accordingly,

4x + 4y = 36

⇒ 4(x + y) = 36

⇒ (x + y) = 9

Now,

9 = 8 + 1

9 = 7 + 2

9 = 6 + 3

9 = 5 + 4

In all these cases only (8,1); (7,2); and (5,4) are prime to each other. So, such three pair is possible

∴ Such three pair of number is possible.

Latest RRB NTPC Updates

Last updated on Jun 27, 2025

-> RRB NTPC Under Graduate Exam Date 2025 will be out soon on the official website of the Railway Recruitment Board. 

-> RRB NTPC Exam Analysis 2025 is LIVE now. All the candidates appearing for the RRB NTPC Exam 2025 can check the complete exam analysis to strategize their preparation accordingly. 

-> The RRB NTPC Admit Card will be released on its official website for RRB NTPC Under Graduate Exam 2025.

-> Candidates who will appear for the RRB NTPC Exam can check their RRB NTPC Time Table 2025 from here. 

-> The RRB NTPC 2025 Notification released for a total of 11558 vacancies. A total of 3445 Vacancies have been announced for Undergraduate posts like Commercial Cum Ticket Clerk, Accounts Clerk Cum Typist, Junior Clerk cum Typist & Trains Clerk.

-> A total of 8114 vacancies are announced for Graduate-level posts in the Non-Technical Popular Categories (NTPC) such as Junior Clerk cum Typist, Accounts Clerk cum Typist, Station Master, etc.

-> Prepare for the exam using RRB NTPC Previous Year Papers.

-> Get detailed subject-wise UGC NET Exam Analysis 2025 and UGC NET Question Paper 2025 for shift 1 (25 June) here

More LCM and HCF Questions

Get Free Access Now
Hot Links: teen patti lotus teen patti master new version teen patti all games teen patti master 2025