পাচঁটি ধারাবাহিক জোড় সংখ্যার গড় হল 16, সংখ্যা গুলির ভেদমান (ভেরিএন্স) কত হবে? 

  1. 40
  2. 16
  3. 8
  4. 10

Answer (Detailed Solution Below)

Option 3 : 8
Free
RRB NTPC CBT-I Official Paper (Held On: 4 Jan 2021 Shift 1)
5.4 Lakh Users
100 Questions 100 Marks 90 Mins

Detailed Solution

Download Solution PDF

প্রদত্ত :

পাচঁটি ধারাবাহিক জোড় সংখ্যার গড় = 16
অনুসৃত সূত্র :  

\({\rm{গড় \;}}\left( {\rm{m}} \right) = \;\frac{{\left\{ {2{\rm{a\;}} + \left( {{\rm{n\;}} - 1} \right){\rm{d}}} \right\}}}{2}\)

V =ভেদমান 

∑ = সমষ্টি 

x = পর্যবেক্ষণ 

n = পর্যবেক্ষণের সংখ্যা 

a = সংখ্যা গুলির 1ম পদ (টার্ম) 

d = সাধারণ অন্তর 

গণনা :

\(\frac{{\left\{ {2{\rm{a\;}} + \left( {{\rm{n\;}} - 1} \right){\rm{d}}} \right\}}}{2} = 16\)

⇒ 2a + (5 – 1)2 = 32

⇒ 2a + 4 × 2 = 32

⇒ 2a = 32 – 8

⇒ 2a = 24

⇒ a = 12

1ম পদ = 12

অন্যান্য পদগুলি হল  14, 16, 18, 20

\({\rm{V}} = {\rm{\;}}\frac{{{{\left( {12{\rm{\;}} - 16} \right)}^2} + {{\left( {14{\rm{\;}} - 16} \right)}^2} + {{\left( {16{\rm{\;}} - 16} \right)}^2} + {{\left( {18{\rm{\;}} - 16} \right)}^2} + {{\left( {20{\rm{\;}} - 16} \right)}^2}}}{5}\)

⇒ \({\rm{\;}}\frac{{16{\rm{\;}} + {\rm{\;}}4{\rm{\;}} + {\rm{\;}}0{\rm{\;}} + {\rm{\;}}4{\rm{\;}} + 16}}{5}\)

⇒ \({\rm{\;}}\frac{{40}}{5}\)

⇒ 8

⇒ V = 8

∴ সংখ্যাগুলির ভেদমান  হল 8

Latest RRB NTPC Updates

Last updated on Jun 9, 2025

-> RRB NTPC 2025 Exam Postponed. Railway Recruitment Board has rescheduled the RRB NTPC Exam for June 5, 2025 (Shift 3). 

-> 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 2025 has been released on its official website.

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

-> The RRB NTPC CBT 1 Exam is scheduled from 5th June to 24th June 2025 as per the revised tentative exam schedule. 

-> The RRB NTPC 2025 Notification has been 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.

-> Check out the Rajasthan PTET Admit Card 2025 and UPSC Prelims Result Date 2025 here.

Get Free Access Now
Hot Links: online teen patti real money teen patti gold real cash teen patti master gold teen patti master 51 bonus teen patti royal - 3 patti