1
Find the simple interest on ₹15,000 at 6% per annum for 4 years.
Correct answer: D. ₹3,600
SI = P × R × T ÷ 100 = 15,000 × 6 × 4 ÷ 100 = ₹3,600.
easy
Simple and Compound Interest MCQs
Solved quantitative aptitude MCQs on simple interest, compound interest, CI–SI difference, half-yearly compounding, growth and depreciation, with formulas and working.
20 MCQsUpdated 27 October 2026
These MCQs cover simple interest, the compound interest formula, compounding half-yearly, finding the rate or principal from an amount, and population growth and depreciation, which use the same formula.
Decide first whether the question is about simple or compound interest. For two years, the difference between CI and SI is P × (R/100)², a shortcut the explanations use.
- 2
₹8,000 amounts to ₹9,920 in 4 years at simple interest. What is the rate of interest per annum?
Correct answer: D. 6%
Interest = 9,920 − 8,000 = ₹1,920. Rate = 1,920 × 100 ÷ (8,000 × 4) = 6%.
easy - 3
At what rate of simple interest per annum will a sum become three times itself in 20 years?
Correct answer: C. 10%
To triple, the interest must equal 2 × the principal, i.e. 200% in 20 years, so the rate is 200 ÷ 20 = 10% per annum.
medium - 4
The simple interest on a sum for 3 years at 8% per annum is ₹1,200. What is the sum?
Correct answer: C. ₹5,000
P = SI × 100 ÷ (R × T) = 1,200 × 100 ÷ 24 = ₹5,000.
easy - 5
A sum at simple interest amounts to ₹7,200 in 2 years and to ₹8,400 in 4 years. What is the sum?
Correct answer: A. ₹6,000
Interest for the extra 2 years = 8,400 − 7,200 = ₹1,200, i.e. ₹600 a year. Interest for 2 years = ₹1,200, so the sum = 7,200 − 1,200 = ₹6,000.
Read detailsmedium - 6
Find the compound interest on ₹5,000 at 10% per annum for 3 years, compounded annually.
Correct answer: C. ₹1,655
Amount = 5,000 × 1.1 × 1.1 × 1.1 = ₹6,655, so CI = ₹1,655. Compare: simple interest would be only ₹1,500.
medium - 7
What amount will ₹20,000 become in 2 years at 5% per annum compound interest (compounded annually)?
Correct answer: D. ₹22,050
Amount = 20,000 × 1.05 × 1.05 = 20,000 × 1.1025 = ₹22,050.
easy - 8
What is the difference between compound interest and simple interest on ₹10,000 at 6% per annum for 2 years?
Correct answer: C. ₹36
For 2 years, CI − SI = P × (R/100)² = 10,000 × 0.06 × 0.06 = ₹36.
medium - 9
Find the compound interest on ₹16,000 for 1 year at 10% per annum, compounded half-yearly.
Correct answer: A. ₹1,640
Half-yearly means 5% for each of 2 periods: 16,000 × 1.05 × 1.05 = ₹17,640, so CI = ₹1,640.
medium - 10
A sum doubles itself in 5 years at compound interest. In how many years will it become 8 times itself?
Correct answer: B. 15 years
At compound interest the sum doubles every 5 years: 2 times after 5, 4 times after 10, 8 times after 15 years.
medium - 11
At what rate of compound interest per annum will ₹6,250 become ₹7,290 in 2 years?
Correct answer: C. 8%
7,290 ÷ 6,250 = 1.1664 = (1.08)², so the rate is 8% per annum.
hard - 12
What is the difference between compound interest and simple interest on ₹1,000 at 10% per annum for 3 years?
Correct answer: C. ₹31
CI = 1,331 − 1,000 = ₹331 and SI = ₹300, so the difference is ₹31.
hard - 13
The population of a town is 50,000 and grows at 4% per year. What will it be after 2 years?
Correct answer: D. 54,080
Population = 50,000 × 1.04 × 1.04 = 54,080 (growth works like compound interest).
medium - 14
A machine worth ₹1,00,000 loses 10% of its value every year. What is its value after 2 years?
Correct answer: C. ₹81,000
Value = 1,00,000 × 0.9 × 0.9 = ₹81,000. Depreciation is applied to the reduced value each year.
medium - 15
Find the simple interest on ₹12,000 at 9% per annum for 6 months.
Correct answer: D. ₹540
Time = 6 months = 1/2 year. SI = 12,000 × 9 × 1/2 ÷ 100 = ₹540.
easy - 16
A sum of money at simple interest becomes 7/5 of itself in 4 years. What is the rate per annum?
Correct answer: A. 10%
Interest = 7/5 − 1 = 2/5 of the sum = 40% in 4 years, so the rate is 40 ÷ 4 = 10% per annum.
medium - 17
Find the compound interest on ₹4,000 for 2 years at 5% per annum, compounded annually.
Correct answer: B. ₹410
Amount = 4,000 × 1.1025 = ₹4,410, so CI = ₹410.
easy - 18
Two equal sums are lent for 3 years at 5% and 7% simple interest per annum. The difference in the interest earned is ₹360. What is each sum?
Correct answer: C. ₹6,000
The difference in rate is 2%, so 360 = P × 2 × 3 ÷ 100, giving P = ₹6,000.
medium - 19
What amount will ₹2,500 become in 5 years at 12% per annum simple interest?
Correct answer: B. ₹4,000
SI = 2,500 × 12 × 5 ÷ 100 = ₹1,500, so the amount is ₹4,000.
easy - 20
What is the effective annual rate of interest when 10% per annum is compounded half-yearly?
Correct answer: B. 10.25%
Each half-year earns 5%: 1.05 × 1.05 = 1.1025, so the effective annual rate is 10.25%.
medium