SSC CGL 2024 Tier-I · 10 September 2024, Shift 3 · Quantitative Aptitude · Question 7 of 100

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 6 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.

Simple interest on a certain sum is one-fifth of the sum and the interest rate per cent per annum is 5 times the number of years. If the rate of interest increases by 3%, then how much will the simple interest (in ₹) be on ₹5,600 for 6 years?

(a)4268
(b)4668
(c)4168
(d)4368

Answer

Why

Correct — D. Two sentences, two equations. Pin the original rate first, then apply the raised rate to the new sum.

SI = P ⁄ 5 and SI = P × R × T ⁄ 100
The sum cancels, leaving R × T = 20

The stem also gives R = 5T:
5T × T = 20 → T² = 4 → T = 2 years
R = 5 × 2 = 10% per annum

Rate rises by 3%, so the new rate is 13%
SI = 5,600 × 13 × 6 ⁄ 100 = 56 × 78 = ₹4,368 → option (d)

Why the others are wrong

(a)
4268 — ₹4,268 is 100 below the answer. With P = 5,600 and T = 6, interest moves ₹336 for each whole percentage point, so 4,268 corresponds to a rate of about 12.7% — no step of this question produces that.
(b)
4668 — ₹4,668 is 300 above. Check the product as 56 × 80 − 56 × 2 = 4,480 − 112 = 4,368 and this option falls away.
(c)
4168 — ₹4,168 matches a rate of roughly 12.4%. The first two sentences fix the original rate at exactly 10%, so after the 3-point rise it can only be 13%.

Concept

Simple interest is SI = P × R × T ⁄ 100. When the interest is given as a fraction of the sum, P cancels and you are left with a relation between R and T alone.

Here SI = P ⁄ 5 gives R × T = 20. The second condition, R = 5T, then forces T² = 4, so T = 2 years and R = 10% per annum.

The second half of the question is a fresh calculation. It borrows only the rate — the ₹5,600 and the 6 years replace the original sum and time entirely.

The original sum is never needed and is never stated. That is deliberate: giving the interest as one-fifth of the sum is what makes the sum cancel.

Key facts

SI = P × R × T ⁄ 100, so 'SI is one-fifth of the sum' means R × T = 20 whatever the sum is.
With R = 5T, T² = 4 gives T = 2 years and R = 10% per annum.
After a 3-point rise the rate is 13%, and 5,600 × 13 × 6 ⁄ 100 = ₹4,368.
For P = 5,600 and T = 6, each 1% of rate is worth ₹336 of interest.

Study next

Simple interest where the principal cancels because SI is a stated fraction of itProblems that link rate and time by a second equation such as R = kTComparing simple interest before and after a change in rate

Common traps

Carrying the 2 years from the first half into the second half, which states 6 years of its own
Reading 'increases by 3%' as a 3% increase on 10%, giving 10.3% instead of 13%
Taking the negative root of T² = 4

SSC writes the first half as two relationships rather than numbers, so a candidate hunting for a principal wastes time on a quantity that cancels. Read the second sentence as a new problem that inherits only the rate.

Related PYQs

No directly related past PYQ was found.