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

Arun and Ajay borrowed Rs.400 each at 10% interest per annum. Arun borrowed at compound interest while Ajay borrowed at simple interest. In both the cases, the interest was calculated half yearly. At the end of one year -

  1. Both paid the same amount as interest

  2. Arun paid Rs.1 more as interest

  3. Ajay paid Rs.5 more as interest

  4. Ajay paid Rs.5 less as interest.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

For Rs. 400 at 10% for 1 year: Simple Interest = 400 * 0.10 = 40. Compound Interest (half-yearly) = 400 * (1 + 0.05)^2 - 400 = 400 * 1.1025 - 400 = 41. The difference is 1.

Multiple choice

A man gave $50\%$ of his savings of $84100$ to his wife and divided the remaining sum among his two sons $A$ and $B$ of $15$ and $13$ years of age respectively. He divided it in such a way that each of his sons, when they attain the age of $20$ years would receive the same amount at $5\%$ compound interest per annum, the share of $B$ was -
  1. $20000$
  2. $20500$
  3. $22000$
  4. $22500$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Savings = 84100. 50% = 42050. Let A's share be x and B's be y. x + y = 42050. x(1.05)^5 = y(1.05)^7. x = y(1.05)^2 = y(1.1025). y(1.1025 + 1) = 42050. y = 42050 / 2.1025 = 20000.

Multiple choice

A sum of $Rs. 2600$ is lent in two parts so that the interest on the first part for a period of $3$ years at $5$% may be equal to the interest on the second part for $6$ years at $4$%. The second part is equal to
  1. $Rs. 1360$
  2. $Rs. 1000$
  3. $Rs. 1440$
  4. $Rs. 720$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Let parts be x and 2600-x. Interest: (x * 3 * 5)/100 = ((2600-x) * 6 * 4)/100. 15x = 24(2600-x). 15x = 62400 - 24x. 39x = 62400, x = 1600. Second part = 2600 - 1600 = 1000.

Multiple choice

The difference between simple interest and compound interest on a certain sum of money at the end of 2 years is Rs. 117 at 15% per annum, the interest being credited annually. The principal is-

  1. Rs. 5,200

  2. Rs. 5,980

  3. Rs. 6,760

  4. None of these.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

For 2 years, the difference between CI and SI is given by P * (r/100)^2. Here, 117 = P * (15/100)^2 = P * (3/20)^2 = P * (9/400). Thus, P = 117 * 400 / 9 = 13 * 400 = 5,200.