Simple Interest Questions Answers

  • 1. 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 And Explanation

    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]

  • 2. 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 And Explanation

    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    Always remember that the day on which money is deposited is not counted while the day on which money is withdrawn is counted.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}

  • 3. 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
    Answer And Explanation

    Answer: Option C

    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}

  • 4. If A lends Rs. 3500 to B at 10% p.a. and B lends the same sum to C at 11.5% p.a., then the gain of B (in Rs.) in a period of 3 years is

    1. Rs. 154.50
    2. Rs. 155.50
    3. Rs. 156.50
    4. Rs. 157.50
    Answer And Explanation

    Answer: Option D

    Explanation:

    We need to calculate the profit of B.
    It will be,
    SI on the rate B lends - SI on the rate B gets

    \begin{aligned}
    \text{Gain of B}\\ &= \frac{3500\times11.5\times3}{100} - \frac{3500\times10\times3}{100}\\
    = 157.50
    \end{aligned}

  • 5. Sahil took a loan for 6 years at the rate of 5% per annum on Simple Interest, If the total interest paid was Rs. 1230, the principal was

    1. 4100
    2. 4200
    3. 4300
    4. 4400
    Answer And Explanation

    Answer: Option A

    Explanation:

    \begin{aligned}
    \text{S.I.} = \frac{P*R*T}{100} \\
    => P = \frac{S.I. * 100}{R*T}
    \end{aligned}

    By applying above formula we can easily solve this question, as we are already having the simple interest.

    \begin{aligned}
    => P = \frac{1230 * 100}{6*5} \\
    => P = 4100
    \end{aligned}

  • 6. There was simple interest of Rs. 4016.25 on a principal amount at the rate of 9%p.a. in 5 years. Find the principal amount

    1. Rs 7925
    2. Rs 8925
    3. Rs 7926
    4. Rs 7925
    Answer And Explanation

    Answer: Option B

    Explanation:

    \begin{aligned}
    P = \frac{S.I. * 100}{R*T}
    \end{aligned}

    So by putting values from our question we can get the answer

    \begin{aligned}
    P = \frac{4016.25 * 100}{9*5} \\
    = 8925
    \end{aligned}

  • 7. 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 And Explanation

    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%