SSC CGL 2024 Tier-I · 9 September 2024, Shift 2 · General Intelligence and Reasoning · Question 16 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 5 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.) (18, 378, 7) (14, 210, 5)

(a)(17, 272, 8)
(b)(17, 204, 6)
(c)(23, 230, 5)
(d)(15, 405, 9)

Answer

Why

Correct — D. Multiply the outer two numbers, then multiply that product by 3.

Rule: middle = first × third × 3.

18 × 7 = 126, and 126 × 3 = 378 ✓
14 × 5 = 70, and 70 × 3 = 210 ✓

Option (d): 15 × 9 = 135, and 135 × 3 = 405 — exactly the middle number offered.

Why the others are wrong

(a)
(17, 272, 8) — 17 × 8 × 3 = 408, not 272. This set uses a multiplier of 2 (17 × 8 × 2 = 272) — self-consistent, but a different rule from the two given sets.
(b)
(17, 204, 6) — 17 × 6 × 3 = 306, not 204. Here too the middle number is twice the product of the outer pair (17 × 6 × 2 = 204) rather than three times it.
(c)
(23, 230, 5) — 23 × 5 × 3 = 345, not 230. Again the multiplier is 2 (23 × 5 × 2 = 230), matching neither of the sets in the stem.

Concept

In a set-relation item the middle number is normally built from the outer two by one arithmetic chain, and the stem's note forbids splitting digits — so you want whole-number operations.

Test the product first. 18 × 7 = 126 against 378 hands you the clean factor 3.

Then check that factor on the second set before you touch the options. That is what proves the multiplier is 3 rather than something that merely happens to fit one set.

All three wrong options are internally consistent on a multiplier of 2.

That is deliberate. Derive the rule from one given set only, and the wrong family looks entirely reasonable.

Key facts

18 × 7 × 3 = 378 and 14 × 5 × 3 = 210.
The rule is middle = first × third × 3.
15 × 9 × 3 = 405, which is option (d).
Options (a), (b) and (c) all use first × third × 2.

Study next

Set relations built on squares, such as middle = first² − thirdNumber analogies where a constant is added after a productSum-and-difference relations across three numbers

Common traps

Deriving the rule from the first set alone — several options fit a single set.
Dividing 378 by 18 to get 21 and then hunting for 21 in the options instead of seeing that 21 = 3 × 7.
Breaking the numbers into digits, which the stem's note explicitly forbids.

SSC gives two model sets and four candidates, and the rule is nearly always a single chain on the whole numbers. The same shift asks the triad version twice more — Reasoning Q.4 (first × second + 11) and Reasoning Q.17 (×2 + 1 at each step), both 9 Sep 2024, 12:30.

Related PYQs

No directly related past PYQ was found.