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

A is drawing Rs.1,000 p.m. on the last day of every month. If the rate of interest is 5% p.a., then the total interest chargeable from him in the accounting year will be ____________.

  1. Rs.325

  2. Rs.275

  3. Rs.300

  4. Rs.350
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

For drawings made at the end of every month, the average period is (11+0)/2 = 5.5 months. Total interest = Total drawings * Rate * Average period / 12 = 12,000 * 0.05 * 5.5 / 12 = 1,000 * 0.05 * 5.5 = 275.

Multiple choice

A and B enter into a joint venture sharing profit and losses in the ratio 3:2. A purchased goods costing Rs. 2,00,000. B sold it for Rs. 3,00,000. He paid 5% of sales as commission. The venture is terminated after 3 months. A is entitled to get 10% p.a. interest on capital invested. The amount of interest received by A will be __________.

  1. 5,000

  2. 2,500

  3. 3,750

  4. 25,000
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A invested 2,00,000. Interest is 10% p.a. for 3 months. Interest = 2,00,000 * 0.10 * (3/12) = 2,00,000 * 0.10 * 0.25 = 5,000.

Multiple choice

A certain amount earns simple interest of rs. 1750 after 7 years . had the interest been 2% more, how much more interest would it have earned?

  1. Rs. 35

  2. Rs. 245

  3. Rs. 350

  4. cannot be determined
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The expression (x-a)(x-10)+1 = x^2 - (a+10)x + (10a+1). For this to factor as (x+alpha)(x+beta) with alpha, beta as integers, the discriminant D = (a+10)^2 - 4(10a+1) must be a perfect square, say k^2. Simplifying, a^2 - 20a + 96 = k^2, which leads to (a-10)^2 - k^2 = 4. The integer solutions for (a-10)^2 - k^2 = 4 are (a-10) = +/- 2, giving a = 12 or a = 8.

Multiple choice

A sum of $Rs.\ 1500$ amounts to $Rs.\ 3000$ in five years at certain rate of simple intersect. If the rate of interest is increased by $1\%$ the same sum in the same time would amount to:
  1. $Rs.\ 3,288$
  2. $Rs.\ 3,312$
  3. $Rs.\ 3,340$
  4. $Rs.\ 3075$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The original simple interest is Rs. 1500 over five years, so the rate is 20% per year. Increasing the rate to 21% gives interest of Rs. 1575, making the amount Rs. 3075.