SSC CGL 2024 Tier-I · 13 September 2024, Shift 2 · General Intelligence and Reasoning · Question 2 of 99

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 triad in which the numbers are related to each other in the same way as the numbers in the following triads. 16-40-100 8-20-50 (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)18-50-110
(b)12-30-120
(c)24-60-150
(d)22-74-185

Answer

Why

Correct — C. Rule: each number is 2.5 times the one before it, so the triad sits in the ratio 4 : 10 : 25.

16 × 2.5 = 40, then 40 × 2.5 = 100.
8 × 2.5 = 20, then 20 × 2.5 = 50.

Option (c): 24 × 2.5 = 60, then 60 × 2.5 = 150.

Both steps hold, so 24-60-150 is the triad.

Why the others are wrong

(a)
18-50-110 — The first step already fails: 18 × 2.5 = 45, not 50. The second fails too, since 50 × 2.5 = 125 rather than 110.
(b)
12-30-120 — The first step works, 12 × 2.5 = 30, but the second does not: 30 × 2.5 = 75, while the option prints 120. A triad must satisfy both steps.
(d)
22-74-185 — Here the back half works, 74 × 2.5 = 185, but the front does not: 22 × 2.5 = 55, not 74. Checking only the later step is what makes this option tempting.

Concept

A triad item gives two worked examples and asks which option obeys the same relation. That relation may be additive, multiplicative or mixed.

Reduce the examples to a ratio first. 16 : 40 : 100 reduces to 4 : 10 : 25, and 8 : 20 : 50 reduces to the same thing, so the relation is a fixed multiplier of 2.5 applied twice.

Working from the ratio is faster than testing options one by one, because it tells you what the middle term must be before you read the choices.

The bracketed rider — operate on the whole number, never on its digits — also appears at Reasoning Q.10, Q.15 and Q.24 of this same 13 Sep 2024, 12:30 paper. It rules out reading 16-40-100 as a digit pattern and forces real arithmetic.

Key facts

16 : 40 : 100 and 8 : 20 : 50 both reduce to the ratio 4 : 10 : 25.
The keyed triad 24-60-150 reduces to 4 : 10 : 25 as well, since 24 is 6 × 4.
A multiplier of 2.5 is the fraction 5/2, so the middle term equals five times the first, halved.

Study next

Reducing a numeric triad to its lowest ratio before testing any optionTriads built on a constant difference rather than a constant ratioTwo-step relations where an option satisfies exactly one of the two steps

Common traps

Testing only the second step, which option (d) satisfies.
Testing only the first step, which option (b) satisfies.
Splitting a number into digits, which the printed note forbids.

Triad items recur across the 2024 Tier-I papers and the engine changes. Reasoning Q.24 of the same 13 Sep 2024, 12:30 paper runs a constant difference of 22 on (148, 126, 104), while 11 Sep 2024, 12:30, Reasoning Q.17 runs double-and-add-one on 8-17-35.

Related PYQs

No directly related past PYQ was found.