SSC CGL 2024 Tier-I · 18 September 2024, Shift 3 · Quantitative Aptitude · Question 20 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.

There is constant growth rate (in %) every year in the production of a company as seen the given table. Year → 2018 | 2019 | 2020 Production (in units) — 9000 | 10,800 | X Find the value of ‘X’ from the data given in the table.

(a)12960
(b)11880
(c)12600
(d)12000

Answer

Why

Correct — A. The stem is an image: a table giving production of 9000 units in 2018, 10,800 in 2019 and X in 2020, with a constant growth rate every year.

Constant rate means each year is the previous year multiplied by the same factor.

Factor = 10800 ⁄ 9000 = 1.2, that is a growth rate of 20%
X = 10800 × 1.2
= 10800 + 2160 = 12960

So X = 12960 units → option (a).

Why the others are wrong

(b)
11880 — 11880 is 10800 grown by 10%. The step the table actually shows, 9000 to 10800, is a rise of 20%, not 10%.
(c)
12600 — 12600 adds the same absolute rise of 1800 units again. The table fixes the rate as constant, not the increment.
(d)
12000 — 12000 needs a factor of 10⁄9, about 11.1% — the factor that would turn 9000 into 10000. The table's factor is 1.2.

Concept

A constant growth rate makes the yearly figures a geometric progression: you multiply by (1 + r) each year, you do not add a fixed amount.

So two consecutive known years are enough. Their ratio is the common factor, and every later year follows from it — production in year n = P(1 + r)ⁿ.

The rival reading, a constant increase, makes an arithmetic progression instead: 9000, 10800, 12600. Both are consistent with the two known cells, which is why the phrase "growth rate (in %)" is doing real work in the stem.

Take the percentage on the base year, not on the later one. 1800 is 20% of 9000 but only about 16.7% of 10,800, and that slip changes the answer.

Key facts

A constant growth rate multiplies each year by the same factor, giving a geometric progression.
10800 ⁄ 9000 = 1.2, so the annual growth rate is 20%.
The sequence 9000, 10800, 12960 has common ratio 1.2.
A constant absolute increase would instead give 9000, 10800, 12600.

Study next

Successive percentage change and the a + b + ab⁄100 shortcutCompound interest, which is this same geometric growth applied to moneyRecovering a growth rate from two terms of a geometric progression

Common traps

Adding 1800 a second time, which assumes a constant increase rather than a constant rate.
Computing the rate as 1800 ⁄ 10800 instead of 1800 ⁄ 9000.
Taking 20% of 9000 and adding it to 10,800.

Percentage change is set in several disguises. As a chain of rises and falls — 18% up, then 15% down, then 3% down on ₹2,00,000 — at Quant Q.6 of this shift.

As a discount to be reversed at Quant Q.4 of this shift, where ₹1,792 after 20% off has to be turned back into the marked price.

Related PYQs

No directly related past PYQ was found.