SSC CGL 2024 Tier-I · 18 September 2024, Shift 1 · General Intelligence and Reasoning · Question 3 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 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 — 20 — 7 5 — 26 — 8 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)8 — 28 — 6
(b)17 — 20 — 13
(c)18 — 70 — 6
(d)5 — 20 — 8

Answer

Why

Correct — A. Rule: the middle number is twice the sum of the outer two.

3 - 20 - 7 gives (3 + 7) x 2 = 10 x 2 = 20
5 - 26 - 8 gives (5 + 8) x 2 = 13 x 2 = 26

Test option (a): 8 - 28 - 6 gives (8 + 6) x 2 = 14 x 2 = 28.

No other set satisfies the rule, so the answer is option (a).

Why the others are wrong

(b)
17 — 20 — 13 — (17 + 13) x 2 = 60, not 20. The outer numbers here are far too large to double up to a middle of only 20.
(c)
18 — 70 — 6 — (18 + 6) x 2 = 48, not 70. Doubling the sum is the relation both given sets obey, and 70 would need a much larger multiplier.
(d)
5 — 20 — 8 — (5 + 8) x 2 = 26, not 20. This option recycles the outer pair of the second given set with the middle number of the first — a deliberate mix.

Concept

Number-set questions ask you to find one arithmetic relation that holds across every given set, then test it on the four options.

Work outward-in. In every set printed here the middle number is much the largest, which points to it being the output of an operation on the two outer numbers.

The NOTE matters. You may add, subtract, multiply or divide the whole numbers, but you may not split 20 into 2 and 0. That bars digit tricks and keeps the search small.

Adding then doubling is the same as multiplying the sum by 2, so the rule can also be written as first + third = half the middle. Whichever form you use, it must fit both given sets.

Key facts

The relation is middle = 2 x (first + third).
(3 + 7) x 2 = 20 and (5 + 8) x 2 = 26, so the rule fits both given sets.
The NOTE forbids breaking any number into its digits.

Study next

Three-term set questions built on first x third plus a constantNumber analogies where one number is a linear function of anotherReading the whole-numbers NOTE before starting the search for a rule

Common traps

Testing the rule on one given set only, then taking the first option that works.
Multiplying the outer pair instead of adding it: 3 x 7 = 21 sits near 20, but 5 x 8 = 40 is nowhere near 26.
Splitting the middle number into digits, which the NOTE bars.

The same set frame with the same whole-numbers NOTE appears at 9 Sep 2024, 12:30, Reasoning Q.16 and at 10 Sep 2024, 09:00, Reasoning Q.9, where the sets are printed as bracketed triples.

Related PYQs

No directly related past PYQ was found.