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 man deposited Rs. 1200 in a recurring deposit account for 1 year at 5% per annum simple interest. The interest earned by him on maturity is:

  1. Rs. 14,790

  2. Rs. 390

  3. Rs. 4680

  4. Rs. 780
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

For a recurring deposit of Rs. 1200 per month for 1 year at 5% simple interest, the interest is calculated on the sum of monthly balances. The total principal is 1200*12 = 14400. The equivalent principal for one month is 1200 * (12*13/2) = 93600. Interest = (P * R * T) / 100 = (93600 * 5 * 1) / (100 * 12) = 390.

Multiple choice

A gave some amount at simple rate of interest of 10% p.a to B for 3 years and B gave this amount to C at the rate of 20% p.a for 3 years. If the income of B was Rs. 1560 after 3 years, what amount A had given to B?

  1. Rs. 6200

  2. Rs. 5400

  3. Rs. 5200

  4. Rs. 5600

  5. Rs. 4800
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Let the amount be P. Interest A pays B = P * 0.1 * 3 = 0.3P. Interest B receives from C = P * 0.2 * 3 = 0.6P. B's income = 0.6P - 0.3P = 0.3P. Given 0.3P = 1560, P = 1560 / 0.3 = 5200.

Multiple choice

A sum of Rs. 91,000 is borrowed at 20% per annum compounded annually for two years. If it were borrowed at the rate of 100/7% per annum simple interest for four years then, find the difference between C.I and S.I

  1. Rs. 16,910

  2. Rs. 12,800

  3. Rs. 12,960

  4. Rs. 11,960

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

CI = 91000 * (1.2^2 - 1) = 91000 * 0.44 = 40040. SI = 91000 * (100/7)/100 * 4 = 91000 * (1/7) * 4 = 52000. The difference is 52000 - 40040 = 11960.

Multiple choice

The rates of simple interest in two banks x and y are in the ratio of 10 : 8. Rajini wants to deposit her total savings in two banks in such a way that she receives equal half-yearly interest from both. She should deposit the savings in banks x and y in the ratio of

  1. 4 : 5

  2. 3 : 5

  3. 5 : 4

  4. 2 : 1

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

Let the interest rates be 10k and 8k, and the amounts deposited be P1 and P2. For equal interest, P1 * 10k = P2 * 8k, which simplifies to P1/P2 = 8/10 = 4/5.

Multiple choice

SBI lent Rs. 10,000 to Deepak @7% SI for 10 years. Meanwhile, the government implemented a scheme due to which interest rate reduced by 2%. By this Deepak paid Rs.16,000 in total. Then after how many years after Deepak took the loan, the government introduced the scheme?

  1. 3 Years

  2. 4 Years

  3. 5 years

  4. 6 years

  5. Cannot be determined
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Let x be the number of years before the scheme was introduced. The interest for the first x years is (10000 * 7 * x) / 100 = 700x. For the remaining (10-x) years, the rate is 5%, so interest is (10000 * 5 * (10-x)) / 100 = 500(10-x). Total amount = Principal + Interest = 10000 + 700x + 5000 - 500x = 16000. Solving 15000 + 200x = 16000 gives 200x = 1000, so x = 5.

Multiple choice

A man invests Rs. 124000 for 9 years at 5% SI. Income tax at the rate of 19% is deducted from interest earned at the end of every year. Find the amount at the end of the 9th year?

  1. Rs. 169198

  2. RS. 169918

  3. Rs. 196918

  4. Rs. 199698

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

Interest each year = 124000 * 0.05 = 6200. Tax = 19% of 6200 = 1178. Net interest = 6200 - 1178 = 5022. Total amount after 9 years = 124000 + (9 * 5022) = 124000 + 45198 = 169198.

Multiple choice

X bought a TV costing 25,000 making down payment of Rs. 5000 and agreeing to make equal annual payment for four years. How much would be each payment if the interest on unpaid amount be 14% compounded annually? [P(4, 0.14) = 2.91731]

  1. Rs. 6855.63

  2. Rs. 6850.63

  3. Rs. 6859

  4. Rs. 6871
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The amount to be financed is 25000 - 5000 = 20000. Using the annuity formula P = A * P(n, i), where P is the principal, A is the annual payment, and P(4, 0.14) is the present value factor, A = 20000 / 2.91731 = 6855.63.

Multiple choice

Amreek invested Rs. x for 2 years at compound interest at 5% p.a. He further invested the amount that he received by investing Rs. x for 2 more years on simple interest at 20% p.a, and eventually received Rs. 46,305. Find the value of x.

  1. Rs. 30,000

  2. Rs. 33,000

  3. Rs. 40,000

  4. Rs. 45,000

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

Amount after 2 years CI = x(1.05)^2 = 1.1025x. Interest on this for 2 years SI at 20% = 1.1025x * 0.2 * 2 = 0.441x. Total = 1.1025x + 0.441x = 1.5435x = 46305. x = 30000.