SSC CGL 2024 Tier-I · 9 September 2024, Shift 3 · General Intelligence and Reasoning · Question 23 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 sets. (34, 47, 62) (119, 142, 167) (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)(64, 78, 99)
(b)(48, 65, 82)
(c)(27, 38, 51)
(d)(79, 98, 119)

Answer

Why

Correct — D. Rule: each set is three consecutive squares, each reduced by 2.

Check the given sets.
34 = 6² - 2, 47 = 7² - 2, 62 = 8² - 2.
119 = 11² - 2, 142 = 12² - 2, 167 = 13² - 2.

Now test the keyed set.
79 = 9² - 2, 98 = 10² - 2, 119 = 11² - 2.

That is (79, 98, 119), option (d).

Why the others are wrong

(a)
(64, 78, 99) — Add 2 to each and you get 66, 80 and 101, none of them a perfect square. Its gaps of 14 and 21 also miss the steady rise of 2 that both given sets show.
(b)
(48, 65, 82) — Its gaps are 17 and 17, an ordinary arithmetic progression. In a run of consecutive squares the gaps have to grow by 2 each time.
(c)
(27, 38, 51) — These are squares plus 2 — 25+2, 36+2, 49+2 — where the given sets are squares minus 2. The gap pattern matches, the constant does not.

Concept

When a three-number set has gaps that grow by a constant, squares are the first family to test. Add or subtract a small constant from each term and look for perfect squares.

Here 34, 47 and 62 sit two below 36, 49 and 64, while 119, 142 and 167 sit two below 121, 144 and 169. Both given sets use consecutive squares, which is the second half of the rule.

The gap test on its own is not enough on this item, because one wrong option obeys it exactly.

Option (c) reproduces the rising gaps of the given sets and is still wrong, which is why the constant has to be checked as well as the shape.

Key facts

34, 47 and 62 are 6² - 2, 7² - 2 and 8² - 2.
119, 142 and 167 are 11² - 2, 12² - 2 and 13² - 2.
The keyed set is 9² - 2, 10² - 2 and 11² - 2.

Study next

Sets built on consecutive squares with a fixed offsetSets built on consecutive cubes and on triangular numbers

Common traps

Stopping at the gap pattern, which two of the four options satisfy.
Taking the constant as +2 rather than -2 because the smaller numbers make the squares easier to spot.

Number-set items recur through this block. 09 Sep 2024, 16:00, Reasoning Q.18 puts n² + 1 on pairs and Q.21 puts a fixed multiplier on triples, so the square family and the product family both appear in one paper.

Related PYQs

No directly related past PYQ was found.