SSC CGL 2024 Tier-I · 10 September 2024, Shift 1 · General Intelligence and Reasoning · Question 15 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 set. (7, 9, 48) (6, 8, 42) (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.)

(a)(10, 12, 54)
(b)(9, 11, 56)
(c)(11, 13, 72)
(d)(8, 10, 47)

Answer

Why

Correct — C.

Rule: third = 3 × (first + second).

Test it on both given sets:
7 + 9 = 16, and 16 × 3 = 48
6 + 8 = 14, and 14 × 3 = 42

Apply it to option (c):
11 + 13 = 24, and 24 × 3 = 72

Why the others are wrong

(a)
(10, 12, 54) — 10 + 12 = 22 and 22 × 3 = 66, not 54. The first two numbers look right because 12 is again two more than 10, but the third number has to be triple the sum.
(b)
(9, 11, 56) — 9 + 11 = 20 and 20 × 3 = 60, not 56. Fifty-six is close enough to catch a hurried eye, which is exactly why the multiplication has to be written down.
(d)
(8, 10, 47) — 8 + 10 = 18 and 18 × 3 = 54, not 47. Forty-seven is also odd, and three times the sum of two even numbers can never be odd.

Concept

Set-relation items give two worked examples and ask for the operation that fits both. One example is never enough, because several rules fit a single line and only one survives the second.

Here 7, 9 to 48 on its own would also fit 7 × 9 − 15 and 7² − 1. Testing 6, 8 to 42 kills both of those and leaves 3 × (a + b) standing.

The bracketed NOTE forbids splitting a number into its digits, so 48 must be handled as forty-eight and not as 4 and 8.

The second number is two more than the first in both given sets and in all four options, so that relation cannot separate them. Only the third number decides the answer.

Key facts

The rule that survives both given sets is third = 3 × (first + second).
A rule that fits only one of the two given sets is not the rule.
The NOTE bars digit-level operations, so 48 is handled as forty-eight.

Study next

Number analogies of the form a : b, where one pair hides the operationOdd-one-out sets in which three of four share an operationTwo-step rules such as (a + b) × k plus a constant, which need both examples to pin down

Common traps

Fitting a rule to the first set and never testing it on the second
Reading the gap between the first two numbers as the relation being tested
Breaking a number into digits after the NOTE has forbidden it

SSC prints this stem with the same bracketed NOTE about whole numbers. Sibling forms sit close by in the same shift: a related-numbers item at Reasoning Q.6 and another set-relation item at Reasoning Q.9.

Related PYQs

No directly related past PYQ was found.