SSC CGL 2025 Tier-I · 13 September 2025, Shift 2 · General Intelligence and Reasoning · Question 8 of 100

We transcribed this text from the pictures on a candidate's response sheet for this shift; the answer is the key SSC colour-marked on that sheet. Solution last reviewed 13 September 2026.

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SSC does not publish CGL question papers or a public answer key. From 2025 the candidate response sheet prints every question and option as a picture, so the text here is transcribed from those pictures for this shift and checked against them independently; where the layout carries meaning, the picture is shown as well. Each answer is the key SSC colour-marked on that sheet. SSC released a tentative key for challenge and later its final one, both only to candidates behind a login, and the sheet does not say which of the two it carries. The solutions are written by UnlockIAS.

Complete the pattern: 120, 96, 76.8, 61.44, ?

(a)60.27
(b)78.91
(c)47.89
(d)49.152

Answer

Why

Correct — D.
Rule: × 0.8 at every step (each term is four-fifths of the one before).

120 × 0.8 = 96
96 × 0.8 = 76.8
76.8 × 0.8 = 61.44
61.44 × 0.8 = 49.152 → option (d).

Why the others are wrong

(a)
60.27 — 60.27 falls only 1.17 below 61.44. Every earlier step removed a fifth of the term, so the next fall must be 61.44 × 0.2 = 12.288.
(b)
78.91 — 78.91 is larger than 61.44, but every term so far is smaller than the one before. The series is falling, so the next term must be below 61.44.
(c)
47.89 — 47.89 is close but not exact: it is about 0.78 of 61.44, not 0.8. The exact product is 61.44 × 0.8 = 49.152, so estimating picks the wrong option.

Concept

When the gaps in a number series shrink, test a ratio before a difference.

The gaps here are 24, 19.2 and 15.36: not constant, but each is 0.8 of the one before. That is what a series multiplied by one fixed number looks like. Divide to confirm: 96 ÷ 120 = 0.8 and 76.8 ÷ 96 = 0.8.

The next gap is 15.36 × 0.8 = 12.288, and 61.44 − 12.288 = 49.152.

Multiplying by 0.8 is easier as × 8, then ÷ 10: 61.44 × 8 = 491.52, and 491.52 ÷ 10 = 49.152.

Key facts

Multiplying by 0.8 is the same as taking 20% off: 120 − 24 = 96.
In a constant-ratio series the gaps shrink by the same ratio: 24, 19.2, 15.36, 12.288.
96 ÷ 120 = 0.8, which is 4⁄5.

Study next

Number series with a constant multiplier greater than 1Series that alternate multiplying and addingConverting a percentage change into a multiplier

Common traps

Estimating the fifth term as about 48 and taking 47.89
Looking for a constant difference, finding none, and guessing

SSC prints this one under the bare instruction Complete the pattern, with no word on whether the step is a gap or a ratio. Decimal terms such as 76.8 and 61.44 are the cue to try a multiplier.

Related PYQs

No directly related past PYQ was found.

Topic: Number Series — all 178 SSC CGL questions on it, every solved shift.