Quantitative Aptitude

Simple and Compound Interest

3,394 Questions
All Simple interest and its inverse forms 768 Compound interest with annual compounding 742 Simple-interest growth and split sums 626 Difference between compound and simple interest 479 Half-yearly and quarterly compounding 252 Changing rates and fractional years 201 Installments (CI based) 190 Ratio of principal to interest 118 Population growth and depreciation 16

Simple and Compound Interest Questions

Multiple choice

Calculate the amount and the compound interest on : Rs. $3,500$ at $10\%$ per annum in $2$ years
  1. Rs. $4,935$ and Rs. $529$.
  2. Rs. $4,235$ and Rs. $735$.
  3. Rs. $3,506$ and Rs. $825$.
  4. Rs. $3,120$ and Rs. $900$.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Using the compound interest formula, the total amount after 2 years is calculated as 3500 * (1 + 10/100)^2, which equals 3500 * 1.21 = Rs. 4,235. The compound interest is the difference between this final amount and the principal, which is 4235 - 3500 = Rs. 735.

Multiple choice

A: Calculate the difference between the simple interest and the compound interest on Rs. $4,000$ in $2$ years at $8 \%$ per annum compounded yearly. B: On a certain sum of money, the difference between the compound interest for a year, payable half-yearly, and the simpled interest for a year is Rs. $180$/-. Find the sum lent out, if the rate of interest in both the cases is $10 \%$ per annum. Then, find $10A + B$.
  1. $72256$
  2. $720256$
  3. $722056$
  4. $722506$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Part A: Difference between CI and SI for 2 years = P * (r/100)^2 = 4000 * (0.08)^2 = 4000 * 0.0064 = 25.6. Part B: Difference between CI (half-yearly) and SI for 1 year = P * ((1 + r/200)^2 - 1) - P * (r/100) = 180. With r=10, P * ((1.05)^2 - 1 - 0.1) = 180 => P * (1.1025 - 1.1) = 180 => P * 0.0025 = 180 => P = 72000. Then 10A + B = 10(25.6) + 72000 = 256 + 72000 = 72256.

Multiple choice

Calculate the amount and the compound interest on Rs. $16,000$ in $3$ years, when the rates of the interest for successive years are $10\%$, $14\%$ and $15\%$ respectively.
  1. Rs. $23.073.60$ and Rs. $7,073.60$
  2. Rs. $23.073.60$ and Rs. $7,873.60$
  3. Rs. $23.873.60$ and Rs. $7,073.60$
  4. Rs. $28.073.60$ and Rs. $7,073.60$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Amount = 16000 * (1.10) * (1.14) * (1.15) = 16000 * 1.4421 = 23073.60. Interest = 23073.60 - 16000 = 7073.60.

Multiple choice

A person borrows a certain amount of money at 5% simple interest and he lends that amount to another person at 10% compound interest, after three years his profit is Rs.905. Find out the amount he borrowed.

  1. Rs. 2000

  2. Rs. 3000

  3. Rs. 5000

  4. Rs. 8000
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Let P be the principal. Simple interest after 3 years is 0.05 * 3 * P = 0.15P. Compound interest after 3 years is P * (1.10^3 - 1) = P * (1.331 - 1) = 0.331P. Profit = 0.331P - 0.15P = 0.181P = 905. P = 905 / 0.181 = 5000.