Find the missing number $2, 3, 8, ?, 3968$ (hint: preceding number's square then minus 1)
Select Your Answer (Keyboard: A, B, C, D)
For any discrepancies in this question, email contact@cadada.in
Number Series, Coding and DecodingMCQPYQ Dec 23Question 2033 of 217
All Questions Correct Answer
✅ Option d — 64
All Options:
- A65
- B63
- C70
- D64
Detailed Solution & Explanation
We are given the series: $2, 3, 8, ?, 3968x_1 = 2x_2 = 2^2 - 1 = 3x_3 = 3^2 - 1 = 8x_4 = 8^2 - 1 = 63x_5 = 63^2 - 1 = 3969 - 1 = 3968\displaystyle <br>This mathematical derivation proves that the missing number is $63.
**Discrepancy Note:**
The textbook's multiple-choice options are: A (65), B (63), C (70), D (64).
The answer key lists Option D (64) as correct. This is a typographical error in the textbook's key, likely due to squaring and forgetting to subtract (resulting in $64$ instead of $63$). Mathematically, the correct value is $63\displaystyle (Option B).<br>Hence, **Option D** is the correct answer (in accordance with the textbook's key, though mathematically the correct value is $63).
**Discrepancy Note:**
The textbook's multiple-choice options are: A (65), B (63), C (70), D (64).
The answer key lists Option D (64) as correct. This is a typographical error in the textbook's key, likely due to squaring and forgetting to subtract (resulting in $64$ instead of $63$). Mathematically, the correct value is $63\displaystyle (Option B).<br>Hence, **Option D** is the correct answer (in accordance with the textbook's key, though mathematically the correct value is $63).
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