SSC CGL 2024 Tier-I · 11 September 2024, Shift 3 · General Intelligence and Reasoning · Question 18 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 6 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.

Four letter-clusters have been given, out of which three are alike in some manner and one is different. Select the one that is different. Note : The odd one out is not based on the number of consonants/vowels or their position in the letter cluster

(a)ONM
(b)BCD
(c)JKL
(d)RST

Answer

Why

Correct — A.

Rule: three consecutive letters, read forwards.

BCD = 2, 3, 4.
JKL = 10, 11, 12.
RST = 18, 19, 20.

Each of those steps +1 then +1 up the alphabet.

ONM = 15, 14, 13. The three letters are consecutive too, but they run the other way, −1 then −1 → option (a).

The note under the question rules out counting vowels and consonants, which is exactly the shortcut ONM would otherwise invite.

Why the others are wrong

(b)
BCD — B, C, D are 2, 3, 4 — consecutive and ascending, the same step as JKL and RST. Being the lowest cluster in the alphabet is a difference of position, not of rule.
(c)
JKL — J, K, L are 10, 11, 12. The step is +1, +1, identical to the other two forward clusters, so nothing marks this one out.
(d)
RST — R, S, T are 18, 19, 20, again three letters in ascending order. Sitting near the end of the alphabet does not change how the cluster is built.

Concept

Odd-one-out on letter clusters is nearly always solved by converting to numbers first. Write the alphabet positions under the letters and the rule usually appears at once.

Here all four clusters are three consecutive letters, so the size of the step cannot separate them. What separates them is direction: three ascend, one descends.

The note attached to the question is doing real work. Without it, ONM could be answered on the vowel it contains, and SSC blocks that route so that the intended property is the only one left.

Among these four clusters, ONM is the one that holds a vowel. That is a true difference, but it is the difference the paper's own note tells you to set aside.

Key facts

B = 2, J = 10 and R = 18, and each of those clusters runs +1, +1.
O = 15, N = 14, M = 13, so ONM descends where the others ascend.
The note excludes vowel and consonant counting as the basis for the answer.

Study next

Odd-one-out clusters where the internal step is +2 or +3 rather than +1Alphabet positions from A = 1 to Z = 26 held in memory both waysReading the note under an SSC question to see which property has been excluded

Common traps

Answering on the vowel in ONM, which the question's own note rules out.
Seeing three consecutive letters and stopping before checking which way they run.
Comparing the clusters with each other instead of testing each one against a single rule.

The same instruction, note and all, is set at 11 Sep 2024, 12:30, Reasoning Q.16 (keyed LKP) and at 17 Sep 2024, 16:00, Reasoning Q.1 (keyed UVXW).

The wording drifts between shifts — 17 Sep drops the Note: label — so read the note rather than recognise it.

The same alphabet-position skill is tested differently at Reasoning Q.6 of this shift, which asks how many letters lie between two letters of a re-ordered word.

Related PYQs

No directly related past PYQ was found.