Number Series, Coding and DecodingPYQ Sept 25Question 4141 of 217

Find the odd one out in the series: 2, 5, 10, 17, 26, 37, 50, 64.

A17

B26

C37

D64

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

Correct Answer

✅ Option d — 64

Let us analyze the terms of the series:

\displaystyle 2, 5, 10, 17, 26, 37, 50, 64

.
Let us check if there is a pattern: -

\displaystyle 2 = 1^2 + 1

\displaystyle 5 = 2^2 + 1

\displaystyle 10 = 3^2 + 1

\displaystyle 17 = 4^2 + 1

\displaystyle 26 = 5^2 + 1

\displaystyle 37 = 6^2 + 1

\displaystyle 50 = 7^2 + 1

The pattern is

\displaystyle T_n = n^2 + 1

. Following this pattern, the next term (for

\displaystyle n=8

) should be:

8^2 + 1 = 64 + 1 = 65

However, the given term is

\displaystyle 64

. Thus, 64 is the odd one out because it does not fit the pattern.
Hence, **Option D** is the correct answer.

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.

Exam Strategy Tip

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

Practice all 217 questions with instant feedback, earn XP, track your streaks, and ace your CA Foundation exam.