SSC CGL 2025 Tier-I · 24 September 2025, Shift 2 · General Intelligence and Reasoning · Question 13 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.

Choose the item that breaks the rule. A5, C7, E9, G11, I10

(a)I10
(b)E9
(c)C7
(d)A5

Answer

Why

Correct — A.
Rule: letters step +2, and each number = letter position + 4.

A(1) + 4 = 5 ✓
C(3) + 4 = 7 ✓
E(5) + 4 = 9 ✓
G(7) + 4 = 11 ✓

I(9) + 4 = 13, but the term reads I10 ✗ → option (a).

Why the others are wrong

(b)
E9 — E9 fits the rule: E is the 5th letter and 5 + 4 = 9. It also keeps the +2 step in the numbers, 7 then 9.
(c)
C7 — C7 fits the rule: C is the 3rd letter and 3 + 4 = 7. It follows A5 with the +2 step in both letter and number.
(d)
A5 — A5 fits the rule: A is the 1st letter and 1 + 4 = 5. It opens the series and sets the +4 link that C7, E9 and G11 keep.

Concept

A letter-number series runs two patterns side by side. Read the letters as positions (A = 1 … Z = 26), check each part on its own, then check how they link.

Here the letters climb A, C, E, G, I and the numbers 5, 7, 9, 11, both by 2. The link, number = position + 4, holds for the first four terms. The fifth needs I13, and I10 falls 3 short.

Two checks agree. The number step (11 + 2 = 13) and the letter link (I = 9, 9 + 4 = 13) both point to I13.

Key facts

Letter positions: A = 1, C = 3, E = 5, G = 7, I = 9.
Each correct term's number is its letter's position plus 4.
The fifth term should read I13.

Study next

Letter-number series with different steps for letters and numbersFinding the wrong term in a number seriesLetter positions counted from Z

Common traps

Checking the letters, which are all in step, and never the numbers

Here SSC gives five letter-number terms and offers four of them as options, with G11 left out.

Related PYQs

No directly related past PYQ was found.

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