SSC CGL 2025 Tier-I · 16 September 2025, Shift 1 · General Intelligence and Reasoning · Question 12 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.

Complete the series. Z1, Y2, X3, W4, ?

(a)V5
(b)V4
(c)U5
(d)X5

Answer

Why

Correct — A.
Rule: letters step back one (Z, Y, X, W); numbers step up one (1, 2, 3, 4).

Next letter: W − 1 = V
Next number: 4 + 1 = 5
V5 → option (a).

Why the others are wrong

(b)
V4 — The letter V is right, but the number repeats 4. The numbers rise by one each term, so the next is 5.
(c)
U5 — U is two letters back from W. The letters step back one at a time (Z, Y, X, W), so the next is V.
(d)
X5 — X is the third term's letter again. The letters keep moving backward, W then V, and never turn back to X.

Concept

A letter–number series runs two series in step. Split each term into its letter and its number, and find each rule separately.

The letters run backwards from the end of the alphabet: Z, Y, X, W, so V comes next. The numbers count up: 1, 2, 3, 4, so 5 comes next. A quick check: letter position plus number is 27 in every term, and V(22) + 5 = 27.

The check works because each step takes one off the letter's position and adds one to the number, so the total never changes.

Key facts

Forward positions of the last letters: Z = 26, Y = 25, X = 24, W = 23, V = 22.
Letter position plus number stays 27 in every term, from Z(26) + 1 to V(22) + 5.

Study next

Letter–number series where the letter steps by twoSeries that alternate a forward and a backward letter

Common traps

Stepping the letter back two, to U
Changing only the letter and leaving the number at 4

17 Sep 2025, 12:30, Reasoning Q.14 uses the same frame running forward: A1, C2, E3, G4, then I5, with the letter stepping +2.

Related PYQs

No directly related past PYQ was found.

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