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

Reena borrowed from Kamila certain sum for two years at simple interest Reena lent this to Hamin at the same rate for two years compound interest At the end of two years she received Rs 110 as compound interest but paid Rs 100 as simple interest Find the sum and rate of interest

  1. Rs 250 and 20%

  2. Rs 250 and 25%

  3. Rs 200 and 20%

  4. Rs 200 and 25%
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

SI = P*R*2/100 = 100. CI = P((1+R/100)^2 - 1) = 110. From SI, P*R = 5000. Substitute into CI: P(2R/100 + R^2/10000) = 110. 2*P*R/100 + P*R^2/10000 = 110. 2*50 + 5000*R/10000 = 110. 100 + R/2 = 110. R/2 = 10, so R = 20%. P = 5000/20 = 250.

Multiple choice

Let Rs. $300$ be borrowed for $8$ months. Then which one of the following will be the correct period of lending of Rs. $400$ in return, provided the rate of interest in both the cases is same and the interest received in each case the same?
  1. $4$ months
  2. $5$ months
  3. $ 5 \displaystyle \frac{1}{2}$ months
  4. $6$ months
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Simple interest formula: I = (P*R*T)/100. Since interest and rate are the same, P1*T1 = P2*T2. 300*8 = 400*T2. T2 = 2400/400 = 6 months.