SSC CGL 2025 Tier-I · 12 September 2025, Shift 2 · General Intelligence and Reasoning · Question 24 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.

If 16+11=A and 1⁄9=B, and A % B=(A×B)−1, then what is A % B?

(a)0
(b)−3
(c)2
(d)5

Answer

Why

Correct — C. Work out A and B, then apply the rule the stem defines.

Rule: A % B = (A × B) − 1.

A = 16 + 11 = 27
B = 1⁄9
A × B = 27 × 1⁄9 = 3
A % B = 3 − 1 = 2, option (c).

Why the others are wrong

(a)
0 — 0 would need A × B = 1, which means A = 9. But 16 + 11 = 27, so A × B = 3.
(b)
−3 — −3 would need A × B = −2. A and B are both positive, so their product is positive, and the result is 3 − 1 = 2.
(d)
5 — 5 would need A × B = 6, which means A = 54, twice the real sum of 27.

Concept

Here % is not a percentage. The stem defines it for this question: A % B = (A × B) − 1. Your job is to substitute, not to guess what the symbol usually means.

Find A and B first, keep B as the fraction 1⁄9, and multiply. 27 is a multiple of 9, so the product is a whole number, 3.

The stem prints B as a stacked fraction, one over nine. Misreading it as 19 or 9 gives 27 × 19 − 1 = 512 or 27 × 9 − 1 = 242, and neither is an option.

Key facts

A = 16 + 11 = 27 and B = 1⁄9.
27 × 1⁄9 = 3, so (A × B) − 1 = 2.
A symbol defined in the stem overrides its everyday meaning.

Study next

Operations defined in the stem, such as a % b = a + 2bMultiplying a whole number by a unit fractionSymbol-substitution puzzles where +, −, × and ÷ are swapped

Common traps

Reading % as a percentage and taking 27 per cent of something.
Forgetting the final − 1 and looking for 3, which is not offered.

An operation defined inside the stem is also set at 12 Sep 2025, 16:00, Reasoning Q.23, where a % b = a + 2b = 37 gives a = 27 and b = 5.

12 Sep 2025, 12:30, Reasoning Q.20 instead makes you rebuild the rule for $ from two samples.

Related PYQs

No directly related past PYQ was found.

Topic: Numerical Operations — all 148 SSC CGL questions on it, every solved shift.