SSC CGL 2024 Tier-I · 18 September 2024, Shift 3 · General Intelligence and Reasoning · Question 3 of 98

Text as printed on a candidate's response sheet for this shift; answer per SSC's tentative key as marked on that sheet. Solution last reviewed 10 September 2026.

Where this paper and its answers come from

SSC does not publish CGL question papers or a public answer key. The questions and options here are reproduced as printed on a candidate's own response sheet for this shift — the Commission's text, unchanged. Each answer is SSC's tentative key as marked on that sheet; SSC allowed challenges to it and never publishes a final key. The solutions are written by UnlockIAS.

Select the set in which the numbers are related in the same way as are the numbers of the following sets. (NOTE: Operations should be performed on the whole numbers, without breaking down the numbers into its constituent digits. E.g. 13 – Operations on 13 such as adding /deleting /multiplying etc. to 13 can be performed. Breaking down 13 into 1 and 3 and then performing mathematical operations on 1 and 3 is not allowed.) (21, 504, 8) (15, 270, 6)

(a)(16, 320, 5)
(b)(16, 336, 7)
(c)(17, 272, 8)
(d)(23, 230, 5)

Answer

Why

Correct — B. Rule: middle number = first × third × 3.

Test it on both given sets:

(21, 504, 8): 21 × 8 = 168, and 168 × 3 = 504
(15, 270, 6): 15 × 6 = 90, and 90 × 3 = 270

Now try option (b), the set (16, 336, 7):

16 × 7 = 112
112 × 3 = 336

The set fits — option (b).

Why the others are wrong

(a)
(16, 320, 5) — 16 × 5 = 80 and 80 × 3 = 240, not 320. 320 is 80 × 4, so this set belongs to the × 4 family, not the × 3 one the given sets use.
(c)
(17, 272, 8) — 17 × 8 = 136 and 136 × 3 = 408. 272 is 136 × 2, so this set doubles where the rule triples.
(d)
(23, 230, 5) — 23 × 5 = 115 and 115 × 3 = 345. 230 is 115 × 2, failing in the same way as option (c).

Concept

Two sample sets are given, and a rule that fits only one of them is not the rule. Multiplying the outer pair and asking what multiple of it the middle number is gets you there fastest: 504 ÷ 168 = 3 and 270 ÷ 90 = 3.

The bracketed NOTE matters. It bars breaking a number into digits, so 504 is 504 and never 5, 0 and 4 — which rules out the digit tricks these sets otherwise invite.

Once the rule is fixed, test the options by computing rather than by eye. Three of the four here are near misses built on × 2 or × 4.

The × 3 and × 4 versions of this rule look identical on the page, and SSC uses both. The multiplier is settled by the two sample sets alone.

Key facts

The NOTE bars digit-splitting: you may operate on 21, never on 2 and 1.
Both sample sets give middle = first × third × 3, so the rule is fixed twice over.
(21, 504, 8) turns up as an option at 9 Sep 2024, 16:00, Reasoning Q.21, where the sample sets run on × 4 and it is the wrong answer.

Study next

Set analogies where the middle number is first × third plus or minus a constantSeparating the × 3 and × 4 families by testing both sample setsThree-number sets whose rule uses addition rather than multiplication

Common traps

Fitting a rule to the first sample set and never checking it against the second
Breaking 504 into digits, which the NOTE forbids
Picking (16, 320, 5) because 320 looks like a clean multiple of 16

SSC re-sets the arithmetic each time: the same three-number frame runs on first × third × 4 at 9 Sep 2024, 16:00, Reasoning Q.21, and on (first + second) × 3 at 10 Sep 2024, 9:00, Reasoning Q.15.

Related PYQs

No directly related past PYQ was found.