SSC CGL 2024 Tier-I · 23 September 2024, Shift 3 · General Intelligence and Reasoning · Question 1 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 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 sequentially placed from left to right in the blanks below, will complete the letter series. _ Y R W I Y _ X I _ R _ I Y R Z

(a)XRYY
(b)IRZY
(c)IYYX
(d)IRYY

Answer

Why

Correct — D. Number the sixteen slots first: the blanks are at positions 1, 7, 10 and 12.

Y is printed at positions 2, 6 and 14, and R at 3, 11 and 15. Every Y sits four or eight slots from the next, and so does every R, which fixes the block at four letters.

Rule: the series is four blocks of four, every block reading I Y R ?, and the tail letters run W, X, Y, Z.

Block 1 = _ Y R W, block 2 = I Y _ X, block 3 = I _ R _, block 4 = I Y R Z.

So the blanks take I (block 1 head), R (block 2 third letter), Y (block 3 second letter) and Y (block 3 tail, sitting between X and Z).

Read left to right that is IRYY — option (d).

Why the others are wrong

(a)
XRYY — Puts X in slot 1, so block one reads X Y R W and the fixed I Y R head is broken at the very first block.
(b)
IRZY — Slot 10 becomes Z, giving block three I Z R Y. The second letter of every block is Y, and Z is already spoken for as the last block's tail.
(c)
IYYX — Slot 7 becomes Y, so block two reads I Y Y X with no R in it, and slot 12 becomes X, repeating the letter that already sits at position 8.

Concept

A blank-filling letter series hides a repeating block. You find the block length before you test a single option, and you find it by looking for a letter that recurs at a fixed gap.

Here the printed Y's fall at 2, 6 and 14 and the R's at 3, 11 and 15 — each set spaced four or eight apart, which is only consistent with a four-letter block.

Once the block is known the series reads as one unchanging head, I Y R, followed by a tail that advances one letter each cycle.

The options are four letters poured into the four blanks in left-to-right order, not four separate candidate answers. Three of the four options open with I, so testing an option against the first blank alone settles nothing.

Key facts

The completed string is I Y R W I Y R X I Y R Y I Y R Z.
The blanks sit at positions 1, 7, 10 and 12, filled in that order by the option's four letters.
The block head I Y R never changes, and only the fourth letter of each block moves — W, X, Y, Z.

Study next

Blank-filling letter series where the repeating block length must be found before any option is testedAlphabet-position work, so an advancing tail such as W, X, Y, Z is recognised on sightLetter series in which the block repeats unchanged except for one advancing slot

Common traps

Treating the four option letters as four separate answers rather than as one left-to-right fill
Testing an option on the first blank only, when three of the four options begin with I
Hunting for a single step rule across all sixteen letters instead of splitting the string into blocks

The blanks sit inside the printed string, so the repeating block has to be found first. The same construction is set at Reasoning Q.20 of this paper, on the series ME_ICM_DIC_GDI_MHD_C.

Related PYQs

No directly related past PYQ was found.

Topic: Semantic Series — all 61 SSC CGL questions on it, every solved shift.