SSC CGL 2024 Tier-I · 11 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.

The same operation(s) are followed in all the given number pairs except one. Find that odd number pair. (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)56 : 9
(b)44 : 7
(c)68 : 11
(d)72 : 12

Answer

Why

Correct — D.

Rule: first number = 6 × second number + 2.

56 : 9 gives 6 × 9 + 2 = 54 + 2 = 56.
44 : 7 gives 6 × 7 + 2 = 42 + 2 = 44.
68 : 11 gives 6 × 11 + 2 = 66 + 2 = 68.

72 : 12 gives 6 × 12 + 2 = 74, not 72.

Read the other way round, (72 − 2) ÷ 6 = 70 ÷ 6, which is not a whole number, so this pair breaks the rule → option (d).

Why the others are wrong

(a)
56 : 9 — 56 = 6 × 9 + 2. It fits the rule the other pairs follow, so it is not the odd one, and it is the pair from which the rule is quickest to spot.
(b)
44 : 7 — 44 = 6 × 7 + 2. Same multiplier, same constant. Being the smallest pair on the list is not a difference in how it is built.
(c)
68 : 11 — 68 = 6 × 11 + 2. The largest of the pairs that fit, and it fits exactly, which confirms the rule rather than straining it.

Concept

The note attached to the question is the instruction that matters: operations act on the whole number, so 56 may not be split into 5 and 6.

That leaves rules of the form a × second + c. Fit one from two pairs and test it on the rest: 56 and 9 with 44 and 7 give a = 6, c = 2 in a single step.

The odd pair here is odd because it fits a tidier rule, 72 = 6 × 12 exactly. That is the shape of the trap: the pair that looks cleanest is the one that has dropped the constant.

Checking by division alone will mislead you. 56 ÷ 9, 44 ÷ 7 and 68 ÷ 11 are all a little over 6, while 72 ÷ 12 is exactly 6, and that exactness reads as correct unless you have already fixed the rule.

Key facts

56 : 9, 44 : 7 and 68 : 11 all satisfy first = 6 × second + 2.
72 : 12 satisfies first = 6 × second, with no constant added.
The note forbids breaking a number into its digits before operating on it.

Study next

Fitting a rule of the form a × b + c from two number pairsOdd-one-out items where the odd pair follows a neater rule than the restReading the whole-number note before testing any relation

Common traps

Accepting 72 : 12 because 72 ÷ 12 = 6 is the cleanest-looking relation on the list.
Testing division only and never a multiply-then-add rule.
Splitting the numbers into digits, which the note in the question rules out.

The instruction and the note are printed verbatim across shifts. 11 Sep 2024, 09:00, Reasoning Q.13 gives 135 : 17, 151 : 19, 128 : 16 and 103 : 13, where the rule is 8 × second − 1 and 128 : 16 is the pair that drops the constant.

09 Sep 2024, 12:30, Reasoning Q.18 uses the same wording again, and the same note appears at Reasoning Q.9, Q.11 and Q.24 of this shift.

Related PYQs

No directly related past PYQ was found.