SSC CGL 2025 Tier-I · 23 September 2025, Shift 1 · General Intelligence and Reasoning · Question 11 of 100

We transcribed this text from the pictures on a candidate's response sheet for this shift; the answer is the key SSC colour-marked on that sheet. Solution last reviewed 13 September 2026.

Where this paper and its answers come from

SSC does not publish CGL question papers or a public answer key. From 2025 the candidate response sheet prints every question and option as a picture, so the text here is transcribed from those pictures for this shift and checked against them independently; where the layout carries meaning, the picture is shown as well. Each answer is the key SSC colour-marked on that sheet. SSC released a tentative key for challenge and later its final one, both only to candidates behind a login, and the sheet does not say which of the two it carries. The solutions are written by UnlockIAS.

What comes next? B25, Y2, C24, X3, ?

(a)V5
(b)E22
(c)D23
(d)W4

Answer

Why

Correct — C.
Rule: two series alternate, odd terms B25, C24 … and even terms Y2, X3 …

Odd terms: letter +1, number −1 → B25, C24, D23.
Even terms: letter −1, number +1 → Y2, X3, then W4.

The missing term is the 5th, an odd term → D23, option (c).

Why the others are wrong

(a)
V5 — V5 belongs to the backward series and, even there, comes after W4. Term 5 is an odd term, which continues B25, C24.
(b)
E22 — E22 skips a letter. After B and C the odd series needs D, and after 25 and 24 the number 23.
(d)
W4 — W4 is the right next even term, but it is term 6. Term 5 is an odd term, and the odd series continues C24 → D23.

Concept

An alternating series interleaves two series. Split the terms by position: the 1st, 3rd and 5th form one series, the 2nd, 4th and 6th the other.

Here each number is also its letter's reverse position. B is 2nd from A and 25th from Z, and Y is 25th from A and 2nd from Z. So B25, C24, D23 walk forward while Y2, X3, W4 walk back from the end.

Every option pairs a letter with its reverse position: V5, E22, D23 and W4 all do. So the pairing cannot decide the answer, and the position in the series does.

Key facts

A letter's forward and reverse positions add to 27: B is 2 and 25, D is 4 and 23.
In an alternating series, the 5th term continues the 1st and 3rd terms.

Study next

Alternating number series with one rising and one falling partLetter-number series that run backwards, such as Z1, Y2, X3Reverse-position codes (Z = 1, A = 26)

Common traps

Continuing the even series and choosing W4 for the 5th term
Treating the five terms as one series and hunting for a single step

16 Sep 2025, 09:00, Reasoning Q.12 runs the backward half of this series on its own: Z1, Y2, X3, W4, keyed V5.

Related PYQs

No directly related past PYQ was found.

Topic: Number Series — all 178 SSC CGL questions on it, every solved shift.