Three of the following four triads are alike in a certain way as they are formed by performing same mathematical operations among themselves and thus form a group. Which triad does NOT belong to that group? 

This question was previously asked in
SSC CGL 2023 Tier-I Official Paper (Held On: 24 Jul 2023 Shift 3)
View all SSC CGL Papers >
  1. 11 : 21 : 121 
  2. 2 : 3 : 4
  3. 7 : 15 : 49
  4. 9 : 17 : 81

Answer (Detailed Solution Below)

Option 3 : 7 : 15 : 49
super-subscription-prototype
Free
PYST 1: SSC CGL - English (Held On : 11 April 2022 Shift 1)
3.1 Lakh Users
25 Questions 50 Marks 12 Mins

Detailed Solution

Download Solution PDF

Logic: [(First no.) : {(First no. × 2) - 1} : (First no.)2]

Checking all the given options:

(1) 11 : 21 : 121 → [(11) : {(11 × 2) - 1} : (11)2]

(2) 2 : 3 : 4 → [(2) : {(2 × 2) - 1} : (2)2]

(3) 7 : 15 : 49 → [(7) : {(7 × 2) + 1} : (7)2]

(4) 9 : 17 : 81 → [(9) : {(9 × 2) - 1} : (9)2]

Here, in (7 : 15 : 49) different logic is followed.

Hence, the correct answer is "7 : 15 : 49".

Latest SSC CGL Updates

Last updated on Jun 11, 2025

-> The SSC CGL Notification 2025 has been released on 9th June 2025 on the official website at ssc.gov.in.

-> The UPSC Prelims Result 2025 and UPSC IFS Result 2025 has been released @upsc.gov.in

-> The SSC CGL exam registration process is now open and will continue till 4th July 2025, so candidates must fill out the SSC CGL Application Form 2025 before the deadline.

-> This year, the Staff Selection Commission (SSC) has announced approximately 14,582 vacancies for various Group B and C posts across government departments.

->  The SSC CGL Tier 1 exam is scheduled to take place from 13th to 30th August 2025.

->  Aspirants should visit ssc.gov.in 2025 regularly for updates and ensure timely submission of the CGL exam form.

-> Candidates can refer to the CGL syllabus for a better understanding of the exam structure and pattern.

-> The CGL Eligibility is a bachelor’s degree in any discipline.

-> Candidates selected through the SSC CGL exam will receive an attractive salary. Learn more about the SSC CGL Salary Structure.

-> Attempt SSC CGL Free English Mock Test and SSC CGL Current Affairs Mock Test.

-> Candidates should also use the SSC CGL previous year papers for a good revision. 

More Number Based Questions

Get Free Access Now
Hot Links: teen patti master list teen patti earning app teen patti party