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 sum of money invested at simple interest becomes Rs. $306$ at the end of $5$ years. If the interest is $\left (\displaystyle \frac{9}{25}\right)^{ th}$ part of the principal, what is the rate of interest per annum ?
  1. $5\dfrac{1}{5} \%$ p.a.
  2. $7\dfrac{1}{5} \%$ p.a.
  3. $9\dfrac{1}{5} \%$ p.a.
  4. $11\dfrac{1}{5} \%$ p.a.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Interest I = (9/25)P. Amount A = P + I = P + 0.36P = 1.36P. 1.36P = 306, so P = 225. Interest I = 306 - 225 = 81. I = (P*R*T)/100 => 81 = (225*R*5)/100. 81 = 11.25R, R = 7.2%. 7.2% is 7 1/5%.

Multiple choice

If Rs.3,750 amount to Rs.4,620 in 3 years at simple interest, then find the rate of interest.
  1. $\displaystyle 7\frac{11}{15}$%
  2. $\displaystyle 8\frac{11}{15}$%
  3. $\displaystyle 6\frac{11}{15}$%
  4. $\displaystyle 5\frac{11}{15}$%
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Simple interest is calculated as SI = A - P = 4620 - 3750 = 870. Using the formula SI = (P * R * T) / 100, we get 870 = (3750 * R * 3) / 100. Solving for R gives R = 87000 / 11250, which simplifies to 7.733 or 7 11/15 percent.

Multiple choice

Y bought a CD Player costing Rs. $13,000$ by making a down payment of Rs. $3,000$ 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?$[P(4, 0.14)2.91371]$
  1. Rs. $3,432.05$
  2. Rs. $3,423.50$
  3. Rs. $3,342.05$
  4. Rs. $3,234.50$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The unpaid amount is Rs. 10,000. With four equal annual payments, the annuity factor is 2.91371, so each payment is 10,000/2.91371 = approximately Rs. 3,432.05.