SSC CGL 2024 Tier-I · 12 September 2024, Shift 3 · General Intelligence and Reasoning · Question 19 of 100

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 6 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 set. 3 — 5 — 30 2 — 4 — 16 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/subtracting/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)

(a)5 — 5 — 45
(b)6 — 6 — 72
(c)9 — 5 — 27
(d)9 — 4 — 7

Answer

Why

Correct — B. Read the operation off both given sets before testing any option.

3 — 5 — 30: 3 × 5 = 15, and 15 × 2 = 30 ✓
2 — 4 — 16: 2 × 4 = 8, and 8 × 2 = 16 ✓

Rule: third = 2 × (first × second).

Apply it to option (b): 6 × 6 = 36, and 36 × 2 = 72, which is the third number printed. Option (b) is the set that matches.

Why the others are wrong

(a)
5 — 5 — 45 — 5 — 5 — 45 gives 5 × 5 = 25, so the rule demands 50. The printed 45 is 5 × 9, an operation neither model set uses.
(c)
9 — 5 — 27 — 9 — 5 — 27 gives 9 × 5 = 45, so the rule demands 90, not 27.
(d)
9 — 4 — 7 — 9 — 4 — 7 gives 9 × 4 = 36, so the rule demands 72. The printed 7 is smaller than the product itself, let alone twice it.

Concept

Set analogies hand you two worked examples so the rule can be cross-checked. A rule read off one set alone is a guess. A rule that survives both is almost always the intended one.

Try the cheap operations in order — sum, difference, product, then the product adjusted by a small multiplier or constant. Here the products are 15 and 8 while the targets are 30 and 16, so the multiplier 2 is visible at once.

SSC's NOTE bars digit-splitting, so 30 may not be taken apart into 3 and 0.

Two of the three wrong sets fail by a wide margin and one, 5 — 5 — 45, misses by only 5. Computing the target rather than eyeballing it is what separates them.

Key facts

The rule is third = 2 × first × second, confirmed on both 3 — 5 — 30 and 2 — 4 — 16.
Option (b) gives 6 × 6 × 2 = 72, matching its printed third number.
A rule verified on one of two model sets is not yet a rule.

Study next

Set analogies whose rule is a product adjusted by a small constantThree-number sets built on the difference of the first twoTelling a genuine rule apart from a coincidence that fits one example

Common traps

Settling on the first operation that fits set one and never testing it on set two.
Reading 30 as 3 and 0 after the NOTE has ruled digit-level work out.

The same select-the-set wording returns at 12 Sep 2024, 16:00, Reasoning Q.21, there with a halve-then-add-10 chain, and SSC's whole-number NOTE is printed on both.

Related PYQs

No directly related past PYQ was found.