24Jun, 2020
Mixed Quantitative Aptitude Questions Set 210
  1. If sum of upstream and between downstream speed of a boat is 80 kmph , and the boat travels 90 km . upstream in 3hr Find the time taken by boat to cover 120 km downstream
    121/5 hr
    13/5 hr
    12/5 hr
    12/7 hr
    12/11 hr
    Option C
    let b= speed of the boat
    w= speed of water
    u= upstream speed= b-w
    d= downstream speed = b+w
    So u +d= 80
    that is b-w+b+w= 80
    =>b= 40
    40-w= 90/3 = 30
    w= 10 kmph
    b+w= 120/t
    t= 120/50 = 12/5 hr

     

  2. The difference between simple interest and compound interest of a certain sum of money at 10 % per annum for 2 years is Rs. 40. Then the sum is ;
    Rs.5000
    Rs.4000
    Rs.6000
    Rs.7000
    Rs.8000
    Option B
    CI- SI = P ( r/100 ) ^2
    40 = p( 10/100) ^2
    => P= Rs.4000

     

  3. Compound interest of a sum of money for 2 years at 4 percent per annum is Rs . 2500 Simple interest of the same sum of money at the same rate of interest for 2 years will be :
    Rs.2350
    Rs.2456
    Rs.2459
    Rs.2450
    Rs.2451
    Option E
    CI= P( 1+r/100 ) ^t – P
    2500 = P (( 1-4/100)^2 -1)
    => p= 2500 * 625 / 51=Rs. 30637.25
    SI= 30,637.25 * 4* 2/100=Rs.2451

     

  4. The are two positive integers a and b . What is the probability that a + b is odd ?
    1/2
    1/3
    1/4
    1/5
    1/6
    Option A
    Sum of positive integers is either odd or even.
    So the probality = 1/2

     

  5. Kailash sells apples at a loss of 44 % but he uses a false scale which is 30 % less than its true weight . Find the loss / gain percent ?
    21%
    22%
    20%
    23%
    24%
    Option C
    Let CP = Rs.100 for 100g
    So SP=Rs. 56 for 70g
    and SP =Rs. 80 for 100g
    loss%=100-80/100 * 100 = 20%

     

  6. Average age of A ,B and C is 80 years . When D joins them the average age becomes 70 years . A new persons E, whose age is 4 years more than D replaces A and the average of B , C, D and E becomes 75 years . What is the age of A ?
    20 yrs
    21 yrs
    22 yrs
    23 yrs
    24 yrs
    Option E
    A+B+C = 3* 80 = 240 yrs
    A+B+C+D= 4* 70 = 280 yrs
    D age= 280-240 = 40yrs
    => E age= 40 + 4 = 44 yrs
    B+C+D+E age = 75* 4= 300 yrs
    B+C age = 300 – 40-44=216
    A age = 240-216=24 yrs

     

  7. The population of sparrows in a particular locality is decreases by certain rate . If the current population of sparrows be 36450 and the ratio of decrease in population for second year and 3rd year be 10 : 9 . What was the population of sparrows 3 years ago ?
    50,000
    55000
    53,000
    52,000
    51,000
    Option A
    Ratio = 10:9
    => 10-9 /10 * 100 = 10%
    So p ( 1-10/100 ) ^3 = 36450
    p= 50,000

     

  8. Tap A can fill a water tank in 25 minutes , tap B can fill the same tank in 40 minutes and tap C can empty the tank in 30 minutes . If all the three taps are opened together , In how many minutes will the tank be completely filled up or emptied ?
    31 3/10 minutes
    26 7/12 minutes
    34 11/19 minutes
    24 1/5 minutes
    31 11/19 minutes
    Option E
    A–> 25
    B—>40
    C—> -30
    Required answer = (25 x 40 x 30) / (40 x 30 + 25 x 30 – 25 x 40)
    == 600 / 19 = 31 11/19 minutes

     

  9. A dog starts to chase a man . When the man goes 20 steps the dog moves 16 steps and 10 steps of the dog are equal to 14 steps of the man . The ratio of the speeds of the dog and the man is :
    28 : 25
    28 : 25
    28 : 25
    28 : 25
    28 : 25
    Option D
    dog : man
    Steps –> 16 : 20
    distance–> 14 : 10
    =224 : 300
    speed= 28 : 25

     

  10. A train runs with a speed of 400 km/hour. What will be its speed in m/sec?
    112.11 m/sec
    111.11 m/sec
    113.11 m/sec
    115.11 m/sec
    117.11 m/sec
    Option B
    Speed in km/ hour =400

    Speed in m/sec = 400 x 5/18 = 500/9 m/sec = 111.11 m/sec