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

Ram borrowed some money at the rate of 6% p.a. for the first three years, 9% p.a. for the next five years and 13% p.a. for the period beyond eight years. If the total interest paid by him at the end of eleven years is Rs. 81600, how much money did he borrow?

  1. Rs. 80000

  2. Rs. 100000

  3. Rs. 120000

  4. Data inadequate
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Interest = P * R * T / 100. Interest = P * (6*3 + 9*5 + 13*3) / 100 = P * (18 + 45 + 39) / 100 = P * 102 / 100. 81600 = 1.02P, so P = 81600 / 1.02 = 80000.

Multiple choice

Mr. Sherpal lends a sum of money to Mr. Kapoor at a certain rate of interest for two years. He is confused whether to lend at simple interest or compound interest. The total compound interest on the amount would be Rs. 1080, whereas the total simple interest would be Rs. 960. What will be the rate if the sum is lend in such a way that simple interest becomes Rs. 3000 and the total number of years is equal to the rate per annum?

  1. 10.5%

  2. 12.5%

  3. 25.0%

  4. 15.5%

  5. 8.5%
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

For 2 years, CI - SI = P(r/100)^2. 1080 - 960 = 120 = P(r/100)^2. Also SI = P*r*T/100 = 960 = P*r*2/100 => P*r = 48000. So P = 48000/r. 120 = (48000/r) * (r^2/10000) = 4.8r. r = 120/4.8 = 25. The second part of the question asks for rate if SI = 3000 and T = r. SI = P*r*r/100 = 3000. Using P = 48000/25 = 1920. 1920 * r^2 / 100 = 3000 => r^2 = 300000/1920 = 156.25. r = 12.5.

Multiple choice

Mr. Vijender went to a bank on Monday and took a loan from the bank at 12% per annum at simple interest. He took the loan in the year 2013. In 2016, Mr. Vijender had to pay Rs. 5,400 as interest only for the period. Find the principal amount borrowed by him.

  1. Rs. 12,000

  2. Rs. 10,000

  3. Rs. 15,000

  4. Rs. 20,000

  5. Rs. 25,000
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Simple Interest = (P * R * T) / 100. Interest = 5400, R = 12, T = 2016 - 2013 = 3 years. 5400 = (P * 12 * 3) / 100. 5400 = 36P / 100. P = 540000 / 36 = 15000.

Multiple choice

Daman purchases a new mobile phone for Rs. 16,000. He had Rs. 4,000 with him that he paid. He paid the rest after 15 months, on which he is charged a simple interest at the rate of 12% per year. Find how much total amount he pays for the mobile phone.

  1. Rs. 17,600

  2. Rs. 17,800

  3. Rs. 17,200

  4. Rs. 17,900

  5. Rs. 17,985
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Principal = 16000 - 4000 = 12000. Interest = P * R * T = 12000 * 0.12 * (15/12) = 12000 * 0.12 * 1.25 = 1800. Total amount = 4000 + 12000 + 1800 = 17800.

Multiple choice

Rupa received cash price of Rs. 1550 for good performance in class in year 2013. She decided to deposit the money in two different banks. She deposited the money partly with ABC Bank at 5% and partly at CBA Bank at 8% p.a. simple interest. The total interest received in 2016 was Rs. 300. How much money did she deposit in CBA Bank?

  1. Rs. 600

  2. Rs. 750

  3. Rs. 800

  4. Rs. 1000

  5. Rs. 1200
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Simple interest I = PRT/100. Let x be amount in ABC bank, 1550-x in CBA bank. Interest = (x*5*3)/100 + ((1550-x)*8*3)/100 = 300. 15x + 37200 - 24x = 30000. 9x = 7200, x = 800. Amount in CBA bank = 1550 - 800 = 750.