Find wrong number of the series $1, 5, 9, 7, 11, 15, 12, 17$
Select Your Answer (Keyboard: A, B, C, D)
For any discrepancies in this question, email contact@cadada.in
Number Series, Coding and DecodingMCQMTP June 22Question 2190 of 217
All Questions Correct Answer
✅ Option b — $12$
All Options:
- A$11$
- B$12$
- C$17$
- D$15$
Detailed Solution & Explanation
Let's analyze the structure of the series: $1, 5, 9, 7, 11, 15, 12, 17+4\displaystyle :<br>- **Group 1**: $1, 5, 9 (starts at , common difference )
- **Group 2**: $7, 11, 157$, common difference $+4\displaystyle )<br>- **Group 3**: $13, 17, 21 (starts at $13$, common difference $+4\displaystyle )<br><br>If we write the full merged series, we get: $1, 5, 9, 7, 11, 15, , 17, 21.
Comparing this to the given series, the term $12$ is incorrect and should be $13$. Therefore, $12$ is the wrong term.
Hence, **Option B** is the correct answer.
- **Group 2**: $7, 11, 157$, common difference $+4\displaystyle )<br>- **Group 3**: $13, 17, 21 (starts at $13$, common difference $+4\displaystyle )<br><br>If we write the full merged series, we get: $1, 5, 9, 7, 11, 15, , 17, 21.
Comparing this to the given series, the term $12$ is incorrect and should be $13$. Therefore, $12$ is the wrong term.
Hence, **Option B** is the correct answer.
About This Chapter: Number Series, Coding and Decoding
Paper
Paper 3: Quantitative Aptitude
Weightage
5 Marks
Key Topics
Number series, Coding & Decoding, Odd man out
This chapter covers Number series, Coding & Decoding, Odd man out and is part of Paper 3: Quantitative Aptitude in the CA Foundation exam.
View Official ICAI SyllabusExam Strategy Tip
This topic carries 5 Marks weightage. Focus on understanding core concepts rather than memorizing.
Related Comparison Tables
More Questions from Number Series, Coding and Decoding
The number in place of question mark in: $7, 26, 63, 124, 215, ?, 511$ is
Find missing term $7, 26, 63, 124, 215, 342, ?$
Which number should come next $7, 26, 63, 124, 215, 342, ?$
If CLOCK is coded as 34235 and TIME as 8679, then MOTEL is coded as:
If MOUSE, is coded as 34651 and KEY is coded as 217, then how will YES be coded?
In a certain code language PREMONITION is written as $68530492904$, how will the word MONITOR be written in that code language?
Ready to Master Number Series, Coding and Decoding?
Practice all 217 questions with instant feedback, earn XP, track your streaks, and ace your CA Foundation exam.
Start Practicing — It's Free