SSC CGL 2025 Tier-I · 12 September 2025, Shift 3 · General Intelligence and Reasoning · Question 19 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 11 September 2026.

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If 5 @ 3 = 28 and 4 @ 2 = 18, then what is 6 @ 4?

(a)40
(b)52
(c)64
(d)76

Answer

Why

Correct — A. Rule: a @ b = a² + b (square the first number, add the second).

5 @ 3 = 25 + 3 = 28 ✓
4 @ 2 = 16 + 2 = 18 ✓

6 @ 4 = 6² + 4
= 36 + 4 = 40 → option (a)

Why the others are wrong

(b)
52 — 52 is 6² + 4², squaring both numbers. That rule gives 5² + 3² = 34 for the first example, not the printed 28.
(c)
64 — 64 would need 28 added to 6² = 36. The examples add only the second number, 3 and then 2, so 6 @ 4 adds 4.
(d)
76 — 76 would need 40 added to 6² = 36, ten times the second number. The examples add the second number itself: 25 + 3 and 16 + 2.

Concept

With a made-up operator, look for a square when each result sits just above one. 28 is 3 more than 25 = 5², and 18 is 2 more than 16 = 4².

The amount over the square is the second number each time. That gives a² + b, which you check against both examples before applying it to 6 @ 4.

Test every rule on both examples. a × b + 13 fits 5 @ 3 = 28 but gives 21 for 4 @ 2, so it is not the rule, while a² + b fits both.

Key facts

5² + 3 = 28 and 4² + 2 = 18.
6² + 4 = 40.
Squares worth knowing on sight: 16, 25, 36, 49, 64, 81.

Study next

Operator rules such as (a + b) × b or (a − b) × bOperator rules that raise the first number to a powerOdd-one-out sets where one pair breaks a shared operator rule

Common traps

Squaring both numbers, which gives 6² + 4² = 52.
Trusting a rule after one example: a × b + 13 fits 5 @ 3 but not 4 @ 2.

An operator rule also decides 14 Sep 2025, 12:30, Reasoning Q.15, where 9 @ 3 = 36 and 6 @ 2 = 16 fit (a + b) × b, and 19 Sep 2025, 09:00, Reasoning Q.20, where 9 % 2 = 81 squares the first number.

Related PYQs

No directly related past PYQ was found.

Topic: Symbolic/Number Analogy — all 169 SSC CGL questions on it, every solved shift.