SSC CGL 2024 Tier-I · 10 September 2024, Shift 1 · General Intelligence and Reasoning · Question 17 of 98

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 B A _ H O L M B A C _ O L M _ A C H O L _ B A C H O L _

(a)CHMBM
(b)CMHBM
(c)CHBMM
(d)CHMMB

Answer

Why

Correct — C.

Rule: the block L M B A C H O repeats, seven letters at a time.

Cut the series into sevens:
L M B A _ H O / L M B A C _ O / L M _ A C H O / L _ B A C H O / L _

Blank 1 sits at position 5 of its block, which is C. Blank 2 is at position 6, which is H. Blank 3 is at position 3, which is B. Blanks 4 and 5 are both at position 2, which is M.

Reading them left to right: C, H, B, M, M — option (c).

Why the others are wrong

(a)
CHMBM — The third blank is wrong. It sits at position 3 of L M B A C H O, which is B and not M, and (a) then puts B where the fourth blank needs M.
(b)
CMHBM — The second blank is wrong. It falls at position 6, which is H, but (b) puts M there and pushes H down into the third slot.
(d)
CHMMB — The third and fifth blanks are wrong. Blank three is at position 3, which is B, and the series ends at position 2 of a fresh block, which is M — (d) ends in B.

Concept

A blank-filling letter series is one repeating block with holes punched in it. The work is in fixing the block length, not in guessing letters.

No block here is printed complete, but two partial blocks overlap and give it away: L M B A _ H O and L M B A C _ O together read L M B A C H O, seven letters.

Once the length is fixed, cut the whole series into sevens and read each blank straight off its position in the block. Nothing else has to be reasoned out.

The cut is easy to check because the letter L opens every group of seven. If a proposed cut puts L anywhere but first, the cut is wrong.

Key facts

The repeating block here is L M B A C H O, seven letters long.
No block in this series is printed complete, so it has to be reconstructed from two partial ones.
Every group of seven opens with L, which is what fixes the cut.

Study next

Letter series whose block shifts one place with each repetitionMissing-term series where the gaps fall on alternate rather than consecutive placesLetter-cluster series driven by alphabet positions instead of a repeating block

Common traps

Guessing the block length from the first blank instead of from the longest clean stretch
Filling the blanks correctly and then writing them out in the wrong order
Assuming the series has to finish on a complete block

The same stem, word for word with a different block, is used on 10 Sep 2024, 12:30, Reasoning Q.9 (D F _ I J O ...) and on 10 Sep 2024, 16:00, Reasoning Q.9 (P Q _ S _ P ...).

Related PYQs

No directly related past PYQ was found.