21Jun, 2021
Quantitative Aptitude: Simple/Compound Interest Set 21
  1. The difference between compound interest and simple interest on rs.42000 at same rate of interest for 2 years is rs.945. What is the rate of interest ?
    10%
    15%
    14%
    20%
    25%
    Option B
    945 = PR^2/100^2
    945 = 42000 * R^2/10000
    R^2 = 225
    R = 15%

     

  2. Rohit borrows rs.4000 at 10% on compound interest and at the end of the every year he paid rs.1000 back. How much amount should he pay at the end of the 3rd year to settlement all his debt ?
    2500
    3000
    3240
    3014
    2480
    Option D
    total amount at the end of the 1st year = 4000 * 110/100 = 4400
    After he paid rs.1000, remaining amount = 4400 – 1000 = 3400
    total amount at the end of 2nd year = 3400 * 110/100 = 3740
    After he paid rs.1000, remaining amount = 3740 – 1000 = 2740
    total amount at the end of 3rd year = 2740 * 110/100 = 3014
    At the end of 3rd year he paid 3014 to settlement his debt.

     

  3. A man borrows rs.8000 for 3 years and he gave at 15%, 20% and 30% rate of interest for 1st year, 2nd year and 3rd year respectively. Then how much amount he paid at the end of 3rd years in compound interest ?
    14435
    14352
    17250
    19540
    20450
    Option B
    Amount in 1st year = 8000 + (8000*15/100) = 9200
    Amount in 2nd year = 9200 + (9200*20/100) = 11040
    Amount in 3rd year = 11040 + (11040 * 30/100) = 14352

     

  4. What is the compound interest on rs.8600 at 20% p.a. for 1 years, compounded half yearly.
    2240
    2420
    1440
    1806
    1425
    Option D
    Rate of interest for 1 year = 20%
    rate of interest for half year = 10%
    by applying successive,
    10 + 10 + 10 * 10/100 = 21%
    compound interest = 8600 * 21/100 = 1806

     

  5. Shivam invested a certain amount at the rate of 14% for 4 years in simple interest and after 4 years he obtained a total simple interest of rs.5600. If invested the same amount at the same rate of interest for 2 years in compound interest then how much interest would he have obtained ?
    3220
    2996
    2834
    2450
    2830
    Option B
    Let principal be rs. x
    = x * 14/100 * 4 = 5600
    x = 5600 * 100/56 = 10000
    by applying successive, rate of compound interest = 14 + 14 + 14 * 14/100 = 19.96%
    compound interest = 10000 * 29.96/100 = 2996

     

  6. The difference between simple interest and compound interest on a certain sum at 20% rate of interest for 2 years is 500. What is difference between simple interest and compound interest for 1st year, if interest is compounded half-yearly ?
    120
    180
    125
    150
    190
    Option C
    500 = PR^2/100^2
    500 = P * 400/10000
    P = 12500
    simple interest for 1st year = 12500 * 20/100 = 2500
    Rate of interest for compound half yearly = 20/2 = 10%
    by apply successive method,
    rate of CI = 10 + 10 + 10 * 10/100 = 21%
    compound interest = 12500 * 21/100 = 2625
    Difference = 2625 – 2500 = 125

     

  7. On a certain sum of money simple interest occurred after 4 years is rs.4800 and compound interest occurred after 2 years is rs.2580. If rate of interest in both cases are same, find the principal amount ?
    12000
    8000
    14000
    18000
    20000
    Option B
    SI after 4 years = 4800
    SI for 1 year = 4800/4 = 1200
    SI for 2 years = 2400
    CI for 2 years = 2580
    by applying SI and CI ratio formula,
    SI/CI = 200/200 + r
    2400/2580 = 200/200 + r
    r = 15%
    Let principal = rs. x
    x * 15/100 * 4 = 4800
    x = 4800*100/60 = 8000

     

  8. What is difference between compound interest and simple interest for 2 years at the rate of 20% on a principal of rs.8500 ?
    240
    520
    340
    624
    125
    Option C
    SI for 2 years = 8500 * 20/100 * 2 = 3400
    by applying successive
    rate of compound interest after 2 years = 20 + 20 + 20 * 20/100 = 44%
    CI = 8500 * 44/100 = 3740
    Difference = 3740 – 3400 = 340

     

  9. If a money get tripled in 5 years on a certain rate of simple interest, then find the rate of interest ?
    20%
    40%
    48%
    45%
    25%
    Option B
    let principal = rs. x
    amount = 3 * x = 3x
    simple interest = 3x – x = 2x
    2x = x * R/100 * 5
    R = 40%

     

  10. Shiva invested rs. X for 4.5 years at the rate of 20% p.a. on simple interest. If he received rs.2520 as interest, then what is the value of X ?
    2800
    1700
    3400
    4600
    3800
    Option A
    2520 = X * 20/100 * 4.5
    X = 2800