WAEC and NECO CBT Software for Computers and Laptops - Candidates, Schools, Centres, Resellers - 100% Offline -Download Now
WAEC and NECO CBT App for Mobile Devices - Candidates, Schools, Centres, Resellers - 100% Offline -Download Now

Given the progression 3, 5, 7, 9,.... . . . find an expression for the...

Mathematics
JAMB 2025

Given the progression 3, 5, 7, 9,.... . . . find an expression for the (n - 2)\(^{th}\) term of the progression.

  • A. \(2n - 1\)
  • B. \(2n + 1\)
  • C. \(2n + 3\)
  • D. \(2n - 3\)
WAEC and NECO CBT App for Mobile Devices - Candidates, Schools, Centres, Resellers - 100% Offline -Download Now
WAEC Past Questions, Objective & Theory, Study 100% offline, Download app now - 127076
Post-UTME Past Questions - Original materials are available here - Download PDF for your school of choice + 1 year SMS alerts
Correct Answer: Option D
Explanation

The sequence 3, 5, 7, 9, ... is an arithmetic progression with:

- First term \(a_1 = 3\)
- Common difference \(d = 2\)

General \(k^{th}\) term:  
\(a_k = 3 + (k-1) \cdot 2 = 2k + 1\)

For the \((n-2)^{th}\) term, substitute \(k = n-2\):  
\(a_{n-2} = 2(n-2) + 1 = 2n - 4 + 1 = 2n - 3\)

The expression is \(2n - 3\) 

There is an explanation video available below.


Report an Error Ask A Question Download App
Post UTME Past Questions Agent
Post-UTME Past Questions - Original materials are available here - Download PDF for your school of choice + 1 year SMS alerts
WAEC offline past questions - with all answers and explanations in one app - Download for free

Explanation Video

WAEC offline past questions - with all answers and explanations in one app - Download for free
WAEC and NECO CBT Software for Computers and Laptops - Candidates, Schools, Centres, Resellers - 100% Offline -Download Now
Post UTME Past Questions Agent

Contributions ({{ comment_count }})

Please wait...

{{ settings.no_comment_msg ? settings.no_comment_msg : 'There are no comments' }}

Quick Questions

Post your Contribution

Please don't post or ask to join a "Group" or "Whatsapp Group" as a comment. It will be deleted. To join or start a group, please click here

{{ quote.posted_by.display_name }}
{{ settings.form_textarea_description }}
 
WAEC offline past questions - with all answers and explanations in one app - Download for free
Post-UTME Past Questions - Original materials are available here - Download PDF for your school of choice + 1 year SMS alerts
WAEC and NECO CBT App for Mobile Devices - Candidates, Schools, Centres, Resellers - 100% Offline -Download Now
WAEC and NECO CBT Software for Computers and Laptops - Candidates, Schools, Centres, Resellers - 100% Offline -Download Now
WAEC Past Questions, Objective & Theory, Study 100% offline, Download app now - 127076
Post UTME Past Questions Agent
WAEC and NECO CBT Software for Computers and Laptops - Candidates, Schools, Centres, Resellers - 100% Offline -Download Now
WAEC offline past questions - with all answers and explanations in one app - Download for free
Post-UTME Past Questions - Original materials are available here - Download PDF for your school of choice + 1 year SMS alerts
Post UTME Past Questions Agent