SSC CGL 2025 Tier-I · 23 September 2025, Shift 1 · General Intelligence and Reasoning · Question 10 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.

Find the pair that does NOT follow the double-step pattern. Q2, R4, S6, T8, V12

(a)Q2
(b)R4
(c)S6
(d)V12

Answer

Why

Correct — D.
Rule: from term to term, the letter moves +1 and the number +2.

Q2 → R4 → S6 → T8: letters Q, R, S, T and numbers 2, 4, 6, 8 ✓
Next should be T + 1 = U with 8 + 2 = 10, that is U10.

V12 jumps two letters and 4 numbers from T8, so it breaks the step → option (d).

Why the others are wrong

(a)
Q2 — Q2 opens the series. R4 is exactly one letter and two numbers on, so Q2 fits the step.
(b)
R4 — R4 follows Q2 by +1 letter and +2, and S6 follows it the same way. Nothing about it breaks the +1, +2 step.
(c)
S6 — S6 sits between R4 and T8, one letter and two numbers from each. It keeps the step on both sides.

Concept

In a letter-number series each term has two parts, and each part runs its own progression. Split them: the letters Q, R, S, T advance one place, the numbers 2, 4, 6, 8 advance two.

To find the misfit, predict each term from the one before it. The first term whose prediction fails is the odd one: after T8 the series needs U10, and V12 appears instead.

Read as separate pairs, V12 still fits a letter-to-number link: number = 2 × (letter position − 16) gives Q 2, R 4, S 6, T 8 and V 12. It breaks only the term-to-term step, where U10 is skipped, and that is the reading the key takes.

Q2, R4 and S6 fit under either reading, so none of them can be the answer.

Key facts

Q, R, S, T, U, V are letters 17 to 22.
A letter-number series splits into a letter series and a number series.
In a +1, +2 series, the term after T8 is U10.

Study next

Letter-number series that run backwards, such as Z1, Y2, X3Series where the letter and the number follow different stepsWrong-term number series

Common traps

Testing each pair on its own, where V12 still fits a formula, instead of the step between terms
Missing the skipped U because V looks like the next letter

16 Sep 2025, 09:00, Reasoning Q.12 builds a letter-number series with the letter falling as the number rises: 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.