SSC CGL 2024 Tier-I · 10 September 2024, Shift 1 · General Intelligence and Reasoning · Question 10 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.

Three of the following four options are alike in a certain way and thus form a group. Which is the option that does NOT belong to that group? (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)2 – 2 – 4
(b)1 – 3 – 3
(c)2 – 4 – 8
(d)3 – 2 – 5

Answer

Why

Correct — D.

Rule: first x second = third.

2 x 2 = 4, so 2 - 2 - 4 fits
1 x 3 = 3, so 1 - 3 - 3 fits
2 x 4 = 8, so 2 - 4 - 8 fits
3 x 2 = 6, but the triple reads 5

The last triple is built on addition instead — 3 + 2 = 5 — so option (d) is the one outside the group.

Why the others are wrong

(a)
2 – 2 – 4 — In 2 - 2 - 4, 2 x 2 = 4, so it obeys the product rule and sits with the others. It also happens to satisfy 2 + 2 = 4, which is why it settles nothing on its own.
(b)
1 – 3 – 3 — In 1 - 3 - 3, 1 x 3 = 3. Multiplying by one leaves the number unchanged and can look like a coincidence, but addition would give 4, so the product rule is what holds.
(c)
2 – 4 – 8 — In 2 - 4 - 8, 2 x 4 = 8 while 2 + 4 is only 6. This is the triple that proves the group's rule is multiplication.

Concept

Three-of-four grouping questions ask for the rule that three entries share, and then name the fourth.

Test the cheapest operations first: addition, subtraction, multiplication. Start with a triple that separates them rather than one that satisfies several.

2 - 2 - 4 fits both 2 + 2 = 4 and 2 x 2 = 4, so it decides nothing. 2 - 4 - 8 and 1 - 3 - 3 each work under multiplication and fail under addition, so the group's rule is the product.

Against that rule 3 - 2 - 5 fails, because 3 x 2 is 6. Its numbers are perfectly orderly under a different operation, which is exactly what makes it the intended odd one.

The stem's NOTE keeps every operation on the whole numbers, so a route through the digits is closed off before you start.

Key facts

2 x 2 = 4, 1 x 3 = 3 and 2 x 4 = 8 all satisfy first times second equals third.
3 x 2 = 6, so 3 - 2 - 5 fails the product rule.
3 + 2 = 5, which is why the odd triple still looks regular at a glance.

Study next

Three-of-four grouping on number triplesChoosing between addition and multiplication when one entry satisfies bothGroups built on squares, cubes or successive differences

Common traps

Starting at 2 - 2 - 4, which fits addition and multiplication equally and proves nothing.
Expecting the odd one out to look irregular, when 3 - 2 - 5 is perfectly regular under addition.

Four triples written with dashes, three sharing one operation. Also asked 10 Sep 2024, 16:00, Reasoning Q.1 (81 - 118 - 91 among four) and 12 Sep 2024, 09:00, Reasoning Q.3.

Related PYQs

No directly related past PYQ was found.