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

The compound interest on a certain sum of money for 2 years at 10% per annum is Rs. 420. Find the simple interest at the same rate and for the same time.

  1. Rs. 400

  2. Rs. 500

  3. Rs. 450

  4. Rs. 550

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

Let P = Rs. x, T = 2 years, R = 10% p.a, and CI = Rs. 420.
Then, A = P(1 + R/100)n A = x(1 + 10/100)2 A = x(11/10)2 A = 121x/100 Because CI = A - P 420 = 121x/100 - x x = 2000 Now, SI = (P * R * T)/100 = (2000 * 10 * 2/100) = Rs. 400 Therefore, the required interest is Rs. 400.

Multiple choice

In simple interest what sum amounts of Rs.1120/- in 4 years and Rs.1200/- in 5 years?

  1. Rs. 500

  2. Rs. 600

  3. Rs. 800

  4. Rs. 900
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Let principal be P and rate be r% per annum. Amount after 4 years = P + (P×r×4)/100 = 1120. Amount after 5 years = P + (P×r×5)/100 = 1200. Subtracting: (P×r)/100 = 80, which is the simple interest for 1 year. Substituting back: P + 320 = 1120, so P = 800. Therefore, Rs. 800 amounts to Rs. 1120 in 4 years and Rs. 1200 in 5 years at simple interest.

Multiple choice

Animesh borrowed Rs. 900 at 4% p.a. and Rs. 1100 at 5% p.a. for the same duration. If he had to pay Rs. 364 in total as the interest, what is the time period that he borrowed the sum for (in years)?

  1. 6

  2. 4

  3. 8

  4. 5

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

Let us assume that the tenure is n years. As the calculation is as per simple interest: Total interest = 900 * 4 * n/100 + 1100 * 5* n/100, i.e. 91n => 91 n = 364 (as per given data) So, n = 4 years, i.e. the tenure is 4 years. So, option 2 is correct.

Multiple choice

The difference between simple interest (SI) and compounded interest (CI) on a certain sum at 10% per annum for 3 years is Rs. 620. Find the principal if the interest is compounded annually.

  1. 28,000

  2. 25,000

  3. 21,000

  4. 24,000

  5. 20,000
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Assume that the sum is X; As per SI /simple interest - interest = 3X/10 = 0.3X As per CI/compound interest - interest = X{ - 1} = 0.331X As per the given data, 0.331X - 0.3X = 620 => X = 20,000

So, option 5 is correct.

Multiple choice

Apurva deposited a certain sum of money in a bank that offered 6% rate of simple interest per annum. At the end of the second year, he received Rs. 150 as interest. How much money will Apurva get at the end of eight years?

  1. Rs. 1850

  2. Rs. 1250

  3. Rs. 650

  4. Rs. 600

  5. Rs. 2100
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Let the money invested by Apurva, i.e. principal be Rs. P. Rate of interest (R) = 6% per annum Time period (T) = 2 years Interest received (I) = Rs. 150 Thus, Apurva had invested Rs. 1250 in funds. At the end of 8 years, she will get Rs. 1850 Option (1) is correct.

Multiple choice

The simple interest on a sum of money will be Rs. 4200 after 8 years. If the principal is doubled after three years, what will be the total interest at the end of 8 years?

  1. Rs. 6825

  2. Rs. 8400

  3. Rs. 9975

  4. Rs. 5250

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

Let the money be p and the rate be r.

Then, p*r*8 = 4200*100            p*r = 52500 Now, for 3 years, SI = p*r*3/100             = 52500*3/100 = 1575 For the next 5 years, money is 2p. So, SI = 2p*r*5/100 = p*r/10             = 52500/10 = 5250 Total SI = 1575+5250 = 6825