SSC CGL 2024 Tier-I · 18 September 2024, Shift 2 · General Intelligence and Reasoning · Question 24 of 99

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 10 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. L M N _ O L L M _ Q O L L _ N Q O _ L M N Q _ L L M

(a)QLMNO
(b)QNMLO
(c)NQLMO
(d)QMNLO

Answer

Why

Correct — B. Rule: the six-letter block L M N Q O L repeats from the very start.

The row is 26 letters long, so the block runs four full times and then breaks off after L M.

Filled in, the row reads
L M N Q O L | L M N Q O L | L M N Q O L | L M N Q O L | L M

The blanks sit at the 4th, 9th, 14th, 18th and 23rd places, which are the block's 4th, 3rd, 2nd, 6th and 5th letters.

Reading them left to right gives Q, N, M, L, O — option (b).

Why the others are wrong

(a)
QLMNO — QLMNO gets the first blank right and then slips. The 9th place is the block's third letter, which is N, not L.
(c)
NQLMO — NQLMO starts wrong. The 4th place is the block's fourth letter, Q, and N has already been used at the 3rd place.
(d)
QMNLO — QMNLO has the second and third blanks the wrong way round. The 9th place needs N and the 14th needs M, not the reverse.

Concept

A blanks-in-a-letter-series item is a periodicity puzzle. The whole task is finding the length of the repeating block; once you have it, the blanks fill themselves.

Find the period from the letters you are given, never from the options. Look for a stretch that recurs at a fixed spacing — the row opens L M N and L M N shows up again six places later, which sets the block at six.

Then index instead of reading. Write the block once, number its places from 1, and reduce each blank's place inside the block. Guessing a blank from the letters beside it is what the swapped-middle options are built to catch.

The block ends in L and the next block opens with L, so the row shows a doubled L in the middle of what looks like a smooth run. That doubling is what makes the period hard to spot by eye.

Key facts

The repeating block is the six letters L M N Q O L.
The 26-letter row is four complete blocks followed by L M.
The blanks fall at the 4th, 9th, 14th, 18th and 23rd places of the row.
Reduced inside the block those are its 4th, 3rd, 2nd, 6th and 5th letters, giving Q, N, M, L, O.

Study next

Letter-series blanks with block lengths of five or sevenSeries printed in lower case, where a repeated letter hides the periodLocating a period by finding the second occurrence of the opening letters

Common traps

Filling each blank from its neighbours rather than from the block, which swaps the middle two.
Missing the doubled L and reading the period as five.
Losing count of the places, since the blanks are not evenly spaced.

The same task appears in lower case and at other block lengths. 13 Sep 2024, 12:30, Reasoning Q.22 runs f h _ h _ g f _ h g _ h _ f f _ g _ h _ f, and 9 Sep 2024, 09:00, Reasoning Q.16 runs L_P_QS_K_P_S_KP_Q_L_ _PQS.

Related PYQs

No directly related past PYQ was found.