SSC CGL 2025 Tier-I · 23 September 2025, Shift 3 · General Intelligence and Reasoning · Question 16 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.

Where this paper and its answers come from

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.

The price of an item first increases by 20% and then decreases by 20% from the new price. What is the net percentage change in the original price of the item?

(a)0.04%
(b)−0.04%
(c)−4%
(d)0%

Answer

Why

Correct — C.
Rule: successive percentage changes multiply — × 1.20, then × 0.80.

Start the price at 100.
Increase 20%: 100 × 1.20 = 120
Decrease 20% of the new price: 120 × 0.80 = 96

Net change: 96 − 100 = −4 on a base of 100
= −4% → option (c).

Why the others are wrong

(a)
0.04% — Wrong sign and wrong size. The price ends at 96, below the starting 100, so the change is negative, and 4 in 100 is 4%, not 0.04%.
(b)
−0.04% — Right direction, wrong size. −0.04 is the fall as a fraction of the price (4⁄100). As a percentage that is −4%, a hundred times larger.
(d)
0% — The two 20% changes act on different bases. +20% of 100 adds 20, but −20% of 120 removes 24, so they do not cancel.

Concept

A percentage change is always taken on the value at that moment. The increase works on the original price, the decrease on the raised price, so equal percentages up and down do not cancel.

The shortcut for two successive changes a% and b% is a + b + ab⁄100. Here: 20 + (−20) + (20 × −20)⁄100 = 0 − 4 = −4%.

Any equal rise and fall of x% ends in a net loss of x²⁄100 per cent, whichever comes first. For 20% that is 400⁄100 = 4%.

Key facts

Successive changes of a% and b% give a net change of a + b + ab⁄100 per cent.
An x% rise followed by an x% fall, in either order, is a net fall of x²⁄100 per cent.
A 20% rise then a 20% fall leaves 96% of the original, a 4% loss.

Study next

Successive discounts, such as 20% and 10% on a marked priceThe percentage rise needed to restore a value after a fallGrowth over two years at different rates

Common traps

Adding the two percentages to get 0% and ignoring that the second acts on a larger base.
Leaving the answer as the fraction −0.04 and reading it as a percentage.

19 Sep 2025, 16:00, Reasoning Q.6 and 24 Sep 2025, 09:00, Reasoning Q.5 ask the same thing about 'a number' instead of a price. Each is keyed 4% decrease.

Related PYQs

No directly related past PYQ was found.