SSC CGL 2025 Tier-I · 17 September 2025, Shift 1 · General Intelligence and Reasoning · Question 19 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.

If 25% of a certain number is 15, what is that number?

(a)45
(b)60
(c)75
(d)90

Answer

Why

Correct — B.
Rule: 25% is one quarter, so the whole is the part multiplied by 4.

25% = 25⁄100 = 1⁄4
1⁄4 of the number = 15
Number = 15 × 4 = 60
Check: 25% of 60 = 60 ÷ 4 = 15 → option (b)

Why the others are wrong

(a)
45 — 45 is 15 × 3, which treats 15 as one-third of the number. A quarter of 45 is 11.25, not 15.
(c)
75 — 75 is 15 × 5, which treats 15 as 20% of the number. A quarter of 75 is 18.75, not 15.
(d)
90 — 90 is 15 × 6, which treats 15 as one-sixth of the number. A quarter of 90 is 22.5, not 15.

Concept

When a percentage of a number is given, divide the part by the percentage written as a fraction: number = part ÷ (p⁄100).

Fraction equivalents make this quick: 25% = 1⁄4, 20% = 1⁄5, 50% = 1⁄2. Dividing by 1⁄4 is the same as multiplying by 4.

Always check back: 25% of 60 is 15, which confirms 60.

Key facts

Number = part × 100 ÷ percentage. Here 15 × 100 ÷ 25 = 60.
25% = 1⁄4, 20% = 1⁄5, 50% = 1⁄2.
Checking back (25% of 60 = 15) catches a wrong fraction at once.

Study next

Percentage-to-fraction equivalents (12.5% = 1⁄8, 33⅓% = 1⁄3)Finding the whole from a part and its percentageThe difference of two percentages of the same number

Common traps

Multiplying 15 by 25% (getting 3.75) instead of dividing by it.
Using the wrong fraction for 25%, such as one-third, which gives 45.

A percent-of-a-number item also appears at 14 Sep 2025, 12:30, Quant Q.4, where 45% of a number is 0.9 more than 30% of it, so 15% is 0.9 and the number is keyed 6.

Related PYQs

No directly related past PYQ was found.