28Jun, 2021
Quantitative Aptitude: Simple/Compound Interest Set 22
  1. Sivam invested some money in a scheme at the rate of 20% for 3 years. If he withdraws 40% of total amount and left remaining amount is rs.2304. What is total money which he invested at earlier.
    2500
    2400
    3500
    3200
    4200
    Option B
    Let principal = 100x
    SI = 100x * 20/100 * 3 = 60x
    Total amount = 100x + 60x = 160x
    remaining = 160x * 60/100 = 96x
    96x = 2304
    x = 24
    He invested = 100x = 2400

     

  2. Simple interest on rs.2750 for 2 years at certain rate of interest is rs.120 more than simple interest on rs.1500 for 3 years at same rate of interest. What is the rate of interest ?
    12%
    14%
    15%
    13%
    18%
    Option A
    Let rate of interest = R%
    (2750*R/100*2) – (1500*R/100*3) = 120
    55 R – 45R = 120
    10 R = 120
    R = 12%

     

  3. Simple interest on a certain sum of money at rate of 20% for 2 years is two times of the compound interest on rs.5000 for 2 years at the rate of 14% per annum. What is the sum on simple interest ?
    8340
    8000
    12000
    7490
    14000
    Option D
    Rate of compound interest after 2 years = 14 + 14 + 14 * 14/100 = 29.96%
    compound interest = 5000 * 29.96/100 = 1498
    simple interest = 1498 * 2 = 2996
    Let principal on simple interest = x
    2996 = x * 20/100 * 2
    x = 7490

     

  4. A man invested an amount of rs.4800 for 3 years a certain rate of simple interest become rs.7248. If the rate of interest increases by 3%, what amount will rs.5000 becomes in 2 years ?
    7200
    6320
    8450
    8240
    6830
    Option A
    Simple interest = 7248 – 4800 = 2448
    2448 = 4800 * 3 * 12/100
    R = 17%
    Now rate of interest = 17 + 3 = 20%
    Amount = 5000 * 120/100 * 120/100 = 7200

     

  5. In how many years a sum will become four times itself at the rate of 12% per annum in simple interest ?
    12 years
    24 years
    25 years
    26 years
    20 years
    Option C
    Let the principal = x
    Amount = 4x
    Simple interest = 4x – x = 3x
    3x = x * 12/100 * T
    T = 25 years.

     

  6. A deposited rs.6800 in a bank at 8% per annum for 5 years simple interest. B deposited rs.8000 at 20% per annum for 2 years in compound interest. What is difference between compound interest and simple interest.
    850
    240
    836
    800
    840
    Option D
    Simple interest = 6800 * 8/100 * 5 = 2720
    By using successive,
    20 + 20 + 20 * 20/100 = 44%
    compound interest = 8000 * 44/100 = 3520
    Difference = 3520 – 2720 = 800

     

  7. A certain sum in simple interest becomes rs.6600 in 4 years and becomes rs.7400 in 6 years, then find the rate of interest.
    4%
    8%
    20%
    14%
    18%
    Option B
    Simple interest for 2 years = 7400 – 6600 = 800
    simple interest for 1 year = 400
    simple interest for 4 years = 4 * 400 = 1600
    sum = 6600 – 1600 = 5000
    1600 = 5000 * R/100 * 4
    R = 8%

     

  8. The difference between compound and simple interests on a sum for 2 years at 15% per annum is 450. Find the sum.
    12000
    25000
    20000
    38000
    35000
    Option C
    CI – SI = PR^2/100^2
    450 = P * 225/10000
    P = 20000

     

  9. The population of a town increased by 25% p.a. If the present population is 50000. Find the population of town 3 years ago.
    25600
    24480
    32540
    24000
    30340
    Option A
    Let the population of town 3 year ago = x
    x * 5/4 * 5/4 * 5/4 = 50000
    x = 50000 * 64/125
    x = 25600

     

  10. What is difference between compound interest and simple interest for 2 years on a principal of rs.4000 at the annual rate of 25% ?
    340
    125
    250
    350
    300
    Option C
    Simple interest = 4000 * 25/100 * 2 = 2000
    Rate of compound interest after 2 years = 25 + 25 + 25 * 25/100 = 56.25%
    compound interest = 4000 * 56.25/100 = 2250
    difference = 2250 – 2000 = 250