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

On a certain sum of money lent out at 16% p.a. the difference between the compound interest for 1 year, payable half yearly, and the simple interest for 1 year is Rs. 56. The sum is

  1. Rs. 1,080

  2. Rs. 7,805

  3. Rs. 8,750

  4. Rs. 5,780

  5. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Simple Interest (SI) = P * 0.16 * 1 = 0.16P. Compound Interest (CI) half-yearly at 16% p.a. means 8% per half-year for 2 periods: CI = P * (1.08^2 - 1) = P * (1.1664 - 1) = 0.1664P. Difference = 0.1664P - 0.16P = 0.0064P = 56. P = 56 / 0.0064 = 8750.

Multiple choice

A sum of Rs. 12,800 is invested partly at 15% per annum and the remaining at 12% per annum simple interest. If the total interest at the end of 3 years is Rs. 5,085, then how much money was invested at 15% per annum?

  1. Rs. 5,200

  2. Rs. 7,500

  3. Rs. 5,800

  4. Rs. 5,300
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Let x be the amount at 15% and (12800 - x) be the amount at 12%. The total interest is given by (x * 0.15 * 3) + ((12800 - x) * 0.12 * 3) = 5085. Solving this linear equation: 0.45x + 4608 - 0.36x = 5085, which simplifies to 0.09x = 477, so x = 5300.

Multiple choice

Mr. Akhil invested Rs. 13,500 in FD. How much will he get on maturity, if he invested it at 20% per annum compound interest for 6 months, compounded quarterly?

  1. Rs. 14,885.35

  2. Rs. 14,883.75

  3. Rs. 14,887.5

  4. Rs. 14,885
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The principal is 13,500, the rate is 20% per annum, and the time is 6 months. Compounded quarterly means the rate per quarter is 5% and the number of periods is 2. Amount = 13,500 * (1 + 0.05)^2 = 13,500 * 1.1025 = 14,883.75.

Multiple choice

A sum of Rs. 10,200 is invested partly at 8% per annum and remaining at 6% per annum for 3 years at simple interest. If the total interest is Rs. 2,124, how much money was invested at 6% per annum?

  1. Rs. 4,900

  2. Rs. 5,200

  3. Rs. 4,800

  4. Rs. 5,400
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Let x be the amount at 8% and (10200-x) at 6%. Interest = (x * 8 * 3)/100 + ((10200-x) * 6 * 3)/100 = 2124. Solving: 24x + 183600 - 18x = 212400, 6x = 28800, x = 4800. Amount at 6% = 10200 - 4800 = 5400.

Multiple choice

Ramesh lends Rs. 50,000 to Suresh and Rajesh at simple interest rate of 10% and 15%, respectively. After 4 years, he earns Rs. 24,000 as interest. Find the amount (in Rs.) that he gave to Suresh and Rajesh, respectively.

  1. 10,000 and 40,000

  2. 15,000 and 35,000

  3. 24,000 and 26,000

  4. 30,000 and 20,000

  5. 40,000 and 10,000
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Let S be amount for Suresh and R for Rajesh. S+R = 50000. Interest: (S*10*4)/100 + (R*15*4)/100 = 24000 => 0.4S + 0.6R = 24000. Solving: 0.4S + 0.6(50000-S) = 24000 => 0.4S + 30000 - 0.6S = 24000 => 0.2S = 6000 => S = 30000. Then R = 20000.

Multiple choice

John and Dave invested the same amount of money at 10% rate of interest for 2 years. John invested money compounded annually. Dave invested money compounded half yearly. The interest received by Dave after 2 years is what percent more than that received by John?

  1. 2.62%

  2. 3.12%

  3. 8.12%

  4. 12.02%

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

John: 10% compounded annually for 2 years = (1.1)^2 - 1 = 21%. Dave: 10% compounded half-yearly for 2 years (4 periods at 5%) = (1.05)^4 - 1 = 21.550625%. Difference = 21.550625 - 21 = 0.550625%. The question asks for percent more, which is (0.550625/21) * 100 = 2.622%.

Multiple choice

Directions: Compare the two quantities in A and B. | Quantity A | Quantity B | | --- | --- | | Compound interest on principal amount of \$10000 at a rate of 10% compounded annually for 2 years | Simple interest on principal amount of \$10000 at a rate of 11% for 2 years |

  1. Quantity A is greater than quantity B.

  2. Quantity B is greater than quantity A.

  3. Both quantities are equal.

  4. Quantity A is either less than or equal to quantity B.

  5. The relationship between the quantities cannot be determined.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Quantity A: 10000 * (1.1^2 - 1) = 10000 * 0.21 = 2100. Quantity B: 10000 * 0.11 * 2 = 2200. Since 2200 > 2100, Quantity B is greater.