SSC CGL 2024 Tier-I · 9 September 2024, Shift 2 · General Intelligence and Reasoning · Question 5 of 100

Text as printed on a candidate's response sheet for this shift; answer per SSC's tentative key as marked on that sheet. Solution last reviewed 5 September 2026.

Where this paper and its answers come from

SSC does not publish CGL question papers or a public answer key. The questions and options here are reproduced as printed on a candidate's own response sheet for this shift — the Commission's text, unchanged. Each answer is SSC's tentative key as marked on that sheet; SSC allowed challenges to it and never publishes a final key. The solutions are written by UnlockIAS.

Select the option that represents the letters that when placed from left to right in the blanks below will complete the given letter series. N _ B A N A _ A _ A N A N A B _ N A N A B A _ A N A

(a)ANANB
(b)NANAB
(c)ANABN
(d)ANBAN

Answer

Why

Correct — D. Rule: the six-letter block N A B A N A, laid end to end.

Number the 26 slots. Every even slot holds A; inside each block the odd slots run N, B, N.

The blanks are slots 2, 7, 9, 16 and 23.

Slot 2 is even → A.
Slot 7 opens a fresh block → N.
Slot 9 is that block's B → B.

Slot 16 is even → A.
Slot 23 is the second N of its block → N.

That gives A N B A N.

Why the others are wrong

(a)
ANANB — Its first two letters are right, but it puts A in slot 9, where the block requires B, and then N in slot 16 — an even slot, and every even slot in this series holds A.
(b)
NANAB — It opens with N in slot 2. Slot 2 is even and every even slot here holds A, so it fails on its very first letter.
(c)
ANABN — Slots 2 and 7 are right, but it puts A in slot 9, where the repeating block N A B A N A requires B.

Concept

A letter-repetition series is one short block laid end to end.

The instinct is to guess the block by ear; the reliable route is to number the slots first, because the blanks are defined by position and one miscount corrupts every blank after it.

Here the visible letters already show A in every even slot, which settles two of the five blanks on the spot. The odd slots then follow the block's own N, B, N.

The block is six letters long while the options are five letters long. The option length matches the number of blanks, not the period of the series, and reading it as a clue to the period is a reliable way to go wrong.

Key facts

The series is the block N A B A N A repeated.
26 slots is four full blocks plus N A.
Every even-numbered slot in this series holds A.
The blanks stand at slots 2, 7, 9, 16 and 23.

Study next

Alphabet series with a growing step, such as +2, +3, +4Missing-letter series in which two patterns alternateSeries whose repeating block lengthens by one letter each cycle

Common traps

Miscounting the slots because the blanks are unevenly spaced
Assuming the block is five letters long because the options are
Filling the blanks by ear, left to right, instead of by slot number

SSC spaces the letters out, marks the blanks with underscores and lists the options in blank order, left to right. The same shift also runs the shifting kind, Reasoning Q.23 and Q.24, where clusters move by fixed alphabet steps instead of repeating.

Related PYQs

No directly related past PYQ was found.