Find the odd one out: 1, 5, 14, 30, 49, 55, 91 .

Option a: 49. Solution: Let's analyze the difference between consecutive terms in the series: - 5 - 1 = 4 = 22 - 14 - 5 = 9 = 32 - 30 - 14 = 16 = 42 - Following the pattern of adding consecutive squares ( 22, 32, 42, 52, 62 ): - The next term should be 30 + 52 = 30 + 25 = 55 . - The term after that should be 55 + 62 = 55 + 36 = 91 . The correct series consists of the square pyramidal numbers 1, 5, 14, 30, 55, 91 . The number 49 does not belong in this series and is the odd man out. Hence, Option A is the correct answer.

Find the odd one out: $1, 5, 14, 30, 49, 55, 91$.

The correct answer is Option a: 49. Let's analyze the difference between consecutive terms in the series: - $5 - 1 = 4 = 2^2$ - $14 - 5 = 9 = 3^2$ - $30 - 14 = 16 = 4^2$ - Following the pattern of adding consecutive squares ($2^2, 3^2, 4^2, 5^2, 6^2$): - The next term should be $30 + 5^2 = 30 + 25 = 55$. - The term after that should be $55 + 6^2 = 55 + 36 = 91$. The correct series consists of the square pyramidal numbers $1, 5, 14, 30, 55, 91$. The number $49$ does not belong in this series and is the odd man out. Hence, **Option A** is the correct answer.

Number Series, Coding and DecodingMCQPYQ Nov. 19Question 2165 of 217

All Questions

Find the odd one out: $\displaystyle 1, 5, 14, 30, 49, 55, 91$ .

Options

A49

B30

C55

D91

For any discrepancies in this question, email contact@cadada.in

Correct Answer

✅ Option a — 49

All Options:

Detailed Solution & Explanation

Let's analyze the difference between consecutive terms in the series:
-

\displaystyle 5 - 1 = 4 = 2^2

\displaystyle 14 - 5 = 9 = 3^2

\displaystyle 30 - 14 = 16 = 4^2

- Following the pattern of adding consecutive squares (

\displaystyle 2^2, 3^2, 4^2, 5^2, 6^2

):
- The next term should be

\displaystyle 30 + 5^2 = 30 + 25 = 55

.
- The term after that should be

\displaystyle 55 + 6^2 = 55 + 36 = 91

.

The correct series consists of the square pyramidal numbers

\displaystyle 1, 5, 14, 30, 55, 91

. The number

\displaystyle 49

does not belong in this series and is the odd man out.

Hence, **Option A** 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 Syllabus

Exam Strategy Tip

This topic carries 5 Marks weightage. Focus on understanding core concepts rather than memorizing.

Related Comparison Tables

Cardinal vs Ordinal Utility: Measuring Satisfaction Promissory Note vs Bill of Exchange: Negotiable Instruments

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

Find the odd one out: 1,5,14,30,49,55,91\displaystyle 1, 5, 14, 30, 49, 55, 911,5,14,30,49,55,91.