Simple Interest Questions and Answers

• 15. Find the rate at Simple interest, at which a sum becomes four times of itself in 15 years.

  1. 10%
  2. 20%
  3. 30%
  4. 40%

  Answer :

  Option B

  Explanation:

  Let sum be x and rate be r%
  then, (x*r*15)/100 = 3x [important to note here is that simple interest will be 3x not 4x, beause 3x+x = 4x]
  
  => r = 20%

• 16. A man took a loan at rate of 12% per annum simple interest. After 3 years he had to pay 5400 interest. The principal amount borrowed by him was.

  1. Rs 14000
  2. Rs 15000
  3. Rs 16000
  4. Rs 17000

  Answer :

  Option B

  Explanation:

  \begin{aligned}
  \text{S.I.} = \frac{P*R*T}{100} \\
  => P = \frac{S.I. * 100}{R*T} \\
  => P = \frac{5400 * 100}{12*3} = Rs 15000
  \end{aligned}

• 17. Sachin borrows Rs. 5000 for 2 years at 4% p.a. simple interest. He immediately lends money to Rahul at 25/4% p.a. for 2 years. Find the gain of one year by Sachin.

  1. 110.50
  2. 111.50
  3. 112.50
  4. 113.50
  5. E, H and J
  6. E, F and G
  7. E, H and G
  8. C, H and J

  Answer :

  Option

  Explanation:

  Two things need to give attention in this question, First we need to calculate gain for 1 year only.
  Second, where we take money at some interest and lends at other, then we use to subtract each other to get result in this type of question. Lets solve this Simple Interest question now.
  
  \begin{aligned}
  \text{Gain in 2 year = } \\
  [(5000 \times \frac{25}{4} \times \frac{2}{100})-(\frac{5000 \times 4 \times 2}{100})] \\
  = (625 - 400) = 225 \\
  \text{ So gain for 1 year = }\\
  \frac{225}{2} = 112.50
  \end{aligned}

• 18. A sum of money at simple interest amounts to Rs. 2240 in 2 years and to Rs. 2600 in 5 years. What is the principal amount

  1. 1000
  2. 1500
  3. 2000
  4. 2500

  Answer :

  Option C

  Explanation:

  
  SI for 3 year = 2600-2240 = 360
  SI for 2 year 360/3 * 2 = 240
  principal = 2240 - 240 = 2000

• 19. Find the simple interest on the Rs. 2000 at 25/4% per annum for the period from 4th Feb 2005 to 18th April 2005

  1. Rs 25
  2. Rs 30
  3. Rs 35
  4. Rs 40

  Answer :

  Option A

  Explanation:

  One thing which is tricky in this question is to calculate the number of days.
  Always remember that the day on which money is deposited is not counted while the day on which money is withdrawn is counted.
  So lets calculate the number of days now,
  Time = (24+31+18) days = 73/365 years = 1/5 years
  P = 2000
  R = 25/4%
  
  \begin{aligned}
  \text{ S.I. = } = \frac{2000 \times 25 }{4 \times 5 \times 100} = 25
  \end{aligned}

• 20. At 5% per annum simple interest, Rahul borrowed Rs. 500. What amount will he pay to clear the debt after 4 years

  1. 750
  2. 700
  3. 650
  4. 600

  Answer :

  Option D

  Explanation:

  We need to calculate the total amount to be paid by him after 4 years, So it will be Principal + simple interest.
  
  So,
  \begin{aligned}
  => 500 + \frac{500*5*4}{100}
  => Rs. 600
  \end{aligned}

• 21. Find the simple interest on Rs 7000 at 50/3 % for 9 months

  1. Rs. 1075
  2. Rs. 975
  3. Rs. 875
  4. Rs. 775

  Answer :

  Option C

  Explanation:

  \begin{aligned}
  \text{ S.I. = } \frac{P \times R \times T}{100}
  \end{aligned}
  So, by putting the values in the above formula, our result will be.
  \begin{aligned}
  \text{ Required result = } \frac{7000 \times 50 \times 9}{3 \times 12 \times 100} = 875
  \end{aligned}
  
  [Please note that we have divided by 12 as we converted 9 months in a year format]