SSC CGL 2024 Tier-I · 17 September 2024, Shift 3 · Quantitative Aptitude · Question 25 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 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.

In how many years will ₹7,200 amount to ₹8,928 at a simple interest rate of 8% per annum?

(a)Five
(b)Three
(c)Four
(d)Two

Answer

Why

Correct — B. Under simple interest each year earns the same amount, so work out one year's interest and see how many of them fit.

Interest earned = 8,928 − 7,200 = ₹1,728
One year's interest = 8% of 7,200 = ₹576
1,728 ÷ 576 = 3

The deposit therefore runs for three years → option (b).
Check: 7,200 + (576 × 3) = 7,200 + 1,728 = ₹8,928.

Why the others are wrong

(a)
Five — Five years would earn 576 × 5 = ₹2,880 in interest and grow the deposit to ₹10,080, well past the ₹8,928 the question states.
(c)
Four — Four years earn ₹2,304 and reach ₹9,504. That overshoots by ₹576 — precisely one year's interest too many.
(d)
Two — Two years earn only ₹1,152 and reach ₹8,352, which is ₹576 short. One further year's interest closes the gap exactly.

Concept

Simple interest is charged on the original principal every year and never on interest already earned. The yearly interest is therefore a fixed amount and the total grows in a straight line.

SI = P × R × T ⁄ 100 rearranges to T = SI × 100 ⁄ (P × R), but in an exam it is quicker to find one year's interest and divide the total interest by it.

The ₹8,928 given is the amount — principal plus interest — so subtract the principal before anything else. Feeding the amount into the formula in place of the interest is what wrecks this question.

At 8% simple interest this deposit earns ₹576 a year however long it runs. Under compound interest the second year would earn on ₹7,776 instead, and ₹8,928 would be passed before the third year was out — so the two schemes part company on exactly the question being asked here.

Key facts

Simple interest is calculated on the original principal for every year of the term.
8% of ₹7,200 is ₹576, the interest earned in each year.
The total interest here is ₹8,928 − ₹7,200 = ₹1,728.
₹1,728 divided by ₹576 gives a term of 3 years.

Study next

Finding the rate when principal, amount and time are givenSimple interest set against compound interest over the same termSums that double or treble themselves under simple interest

Common traps

Treating ₹8,928 as the interest rather than as the amount
Taking 8% of the amount, ₹8,928, instead of 8% of the principal
Rounding 8% of 7,200 to ₹570 and losing the exact division by 576

A simple-interest item hands over three of the four quantities — principal, rate, time, amount — and asks for the fourth. Here the amount arrives in place of the interest.

Interest as a percentage of a deposit also appears at Quant Q.2 of this paper, where a bank pays 6% on deposits and earns ₹30,000 for every ₹3,00,000 it invests.

Related PYQs

No directly related past PYQ was found.