SSC CGL 2025 Tier-I · 19 September 2025, Shift 2 · Quantitative Aptitude · 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.

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.

At what rate of simple interest will ₹2,000 become ₹2,520 in 4 years?

(a)7.5%
(b)6.5%
(c)7.8%
(d)6.8%

Answer

Why

Correct — B.
Simple interest = amount − principal
2520 − 2000 = ₹520

Interest for one year: 520 ÷ 4 = ₹130
Rate = one year's interest as a percentage of the principal
130 ÷ 2000 × 100 = 6.5

So the rate is 6.5% per annum → option (b)

Why the others are wrong

(a)
7.5% — At 7.5%, four years' interest is 2000 × 7.5 × 4 ÷ 100 = ₹600, so the sum would become ₹2,600, not ₹2,520.
(c)
7.8% — At 7.8%, four years' interest is ₹624 (2000 × 7.8 × 4 ÷ 100), taking the sum to ₹2,624. The interest actually earned is only ₹520.
(d)
6.8% — At 6.8%, four years' interest is ₹544 (2000 × 6.8 × 4 ÷ 100), giving ₹2,544. That is ₹24 more than the ₹520 earned.

Concept

Simple interest is charged on the original principal only, so the same interest accrues every year: SI = P × R × T ÷ 100.

Rearranged for the rate, R = SI × 100 ÷ (P × T). The amount includes the principal, so subtract it first: SI = A − P.

Here R = 520 × 100 ÷ (2000 × 4) = 52000 ÷ 8000 = 6.5.

A bound narrows the options before any division. At 6% the interest would be ₹480 and at 7% it would be ₹560, so the rate lies between 6% and 7%. That leaves 6.5% and 6.8%, and only 6.5% gives exactly ₹520.

Key facts

SI = P × R × T ÷ 100
R = SI × 100 ÷ (P × T)
Amount = principal + simple interest
Each 1% a year on ₹2,000 for 4 years adds ₹80, and 520 ÷ 80 = 6.5

Study next

Finding the time when principal, amount and rate are givenA sum that becomes n times itself at simple interest, where SI = (n − 1) × PFinding the principal and rate from two amounts at two different times

Common traps

Putting the amount ₹2,520 into the formula as the interest, which gives 31.5%
Stopping at 520 ÷ 2000 = 26% and forgetting to divide by the 4 years

19 Sep 2024, 12:30, Quant Q.25 is the same calculation: ₹1,456 amounts to ₹2,366 in ten years, so SI = ₹910 and R = 910 × 100 ÷ (1456 × 10) = 6.25%.

11 Sep 2024, 12:30, Quant Q.25 solves the same formula for time: ₹8,400 grows to ₹11,928 at 7%, and 3528 ÷ 588 = 6 years.

Related PYQs

No directly related past PYQ was found.

Topic: Interest — all 82 SSC CGL questions on it, every solved shift.