SSC CGL 2025 Tier-I · 17 September 2025, Shift 2 · General Intelligence and Reasoning · Question 14 of 99

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. A1, C2, E3, G4, ?

(a)J5
(b)K5
(c)H5
(d)I5

Answer

Why

Correct — D.
Rule: letters move +2, numbers move +1.

Letters: A(1), C(3), E(5), G(7) → next is I(9).
Numbers: 1, 2, 3, 4 → next is 5.

Put together: I5 → option (d).

Why the others are wrong

(a)
J5 — J is G + 3. The number 5 fits, but the letters step by 2 (A, C, E, G), so the letter after G is I.
(b)
K5 — K is G + 4, two places too far. Only the number part, 5, follows the series. The letter must be I.
(c)
H5 — H is G + 1: it moves the letter by the number step. The letters jump 2 places each time, so after G comes I.

Concept

A term such as C2 carries two sequences side by side: a letter and a number. Split every term into its two parts and find the step of each part separately.

Here the letters take the odd alphabet positions 1, 3, 5, 7, so the next is position 9, I. The numbers simply count up to 5. Join the two parts only at the end.

A quick check: in every term the letter's position is 2 × number − 1. C is 3 = 2 × 2 − 1, G is 7 = 2 × 4 − 1, and I is 9 = 2 × 5 − 1.

Key facts

A = 1, C = 3, E = 5, G = 7, I = 9: the first five odd alphabet positions.
The numbers 1, 2, 3, 4, 5 equal each term's place in the series.
E = 5, J = 10, O = 15, T = 20 are quick anchors for counting alphabet positions.

Study next

Letter-number series with the letters running backwards, such as Z1, Y2, X3Finding the term that breaks a letter-number patternLetter series whose step grows, such as +1, +2, +3

Common traps

Moving the letter by the number step (+1) and choosing H5
Skipping two letters after G (H and I) instead of one, which lands on J

16 Sep 2025, 09:00, Reasoning Q.12 runs the letters backwards: Z1, Y2, X3, W4, keyed V5.

24 Sep 2025, 12:30, Reasoning Q.13 asks which term breaks A5, C7, E9, G11, I10, keyed I10 (the pattern needs I13).

Related PYQs

No directly related past PYQ was found.

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