Mixed Quantitative Aptitude Questions Set 56

Quantitative Aptitude Questions for IBPS RRB/PO/Clerk, SBI PO, NIACL, NICL, RBI Grade B/Assistant, BOI, Bank of Baroda and other competitive exams

1. A boat takes 90 minutes less to travel 36 km downstream than to travel the same distance upstream. If the speed of the boat in still water is 10 km/h, the speed of the stream is:
   A) 3km/hr
   B) 1.5km/hr
   C) 2km/hr
   D) 4km/hr
   E) None
   
   View Answer

   Option C
   Solution:
   Let the speed of the stream x km/hr.
   Then downstream =(10+x)
   Upstream =(10-x)
   36/(10-x) – 36/(10+x) =90/60
   72x *60=90(100-x² )
   x²+48x-100=0
   x=2km/hr.
2. In an exam out of 1800 students, 65% boys and 80% girls are passed. If total pass percentage was 75% , how many girls appeared in the exam and how many girls failed?
   A) 1350, 360
   B) 1200, 240
   C) 1000, 180
   D) 1050, 280
   E) None
   
   View Answer

   Option B
   Solution:
   B65 …………………G80
   .               75
   5 ……………………..10
   Ratio 1:2.
   Number of Girls 1800*2/3=1200.
   Then No of girls failed=1200*20/100=240.
3. The average temperature for Wednesday, Thursday and Friday was 42 Deg c. The average for Thursday, Friday and Saturday was 43 Deg c. If temperature on Saturday was 44 Deg c, what was the temperature on Wednesday?
   A) 47 Deg c
   B) 43 Deg c
   C) 45 Deg c
   D) 41 Deg c
   E) None
   
   View Answer

   Option D
   Solution:
   Average temperature for Wednesday, Thursday and Friday = 42 Deg c
   Total temperature = 3*42 = 126 Deg c
   Average temperature for Thursday, Friday and Saturday = 43 Deg c
   Total temperature = 43*3 = 129 Deg c
   Temperature on Saturday = 44 Deg c
   Now ,
   (Thursday + Friday + Saturday) – (Wednesday + Thursday + Friday) = 129-126
   Saturday – Wednesday = 3
   Wednesday = 44-3 = 41 Deg c.
4. Find the average of first 85 natural numbers.
   A) 43
   B) 50
   C) 48
   D) 53
   E) None
   
   View Answer

   Option A
   Solution:
   Average of 1st n natural number is given by = ([n*(n+1)]/2)/n
   Average of 1st 85 natural number is given by
   {([85*(86)]/2)/85} =43.
5. On a road three consecutive traffic lights change after 40, 48 and 56 seconds respectively. If the lights are first switched on at 10:00 AM sharp, at what time will they change simultaneously?
   A) 10.35m
   B) 10.28am
   C) 10.40am
   D) 10.43am
   E) None
   
   View Answer

   Option B
   Solution:
   LCM of 40,48,56=1680sec
   Hence, the lights will change simultaneously after 28 minutes.
6. Find the least number of five digits which when divided by 40, 60, and 75, leave remainders 31, 51 and 66 respectively.
   A) 10136
   B) 10102
   C) 10191
   D) 10111
   E) None
   
   View Answer

   Option C
   Solution:
   Difference, 40-31 = 9
   60-51 = 9
   75-66 = 9
   Difference between numbers and remainder is same in each case.
   Then ,
   The answer = {(LCM of 40, 60, 75)-9}
   LCM = 600
   But, the least number of 5 digits = 10000
   10000/600, we get remainder as 400.
   Then, the answer = 1000-(600-400)-9; = 10191.
7. X takes 4 days to complete one-third of a job. Y takes 3 days to complete one-sixth of the job and Z takes 5 days to complete half the job. If all of them work together for 3 days and X and Z quit, how long will it take for Y to complete the remaining work done.
   A) 6
   B) 5 1/10
   C) 4 2/3
   D) 7
   E) None
   
   View Answer

   Option B
   Solution:
   X one day work 1/12
   Y one day work 1/18
   Z one day work 1/10
   Let Y take n days to complete remaining work then
   3/12 +3/18+ 3/10+n/18=1
   n/18= 1-1/4-1/6-3/10
   n/18=17/60
   n= (17*18)/60=5 1/10 days.
8. An Employer pays Rs. 15 for each day a worker works, and forfeits Rs. 5 for each day he is idle. At the end of 40 days, a worker gets Rs. 160. For how many days did the worker remain idle?
   A) 26
   B) 28
   C) 18
   D) 22
   E) None
   
   View Answer

   Option D
   Solution:
   Suppose the worker remained idle for x days. Then,
   He worked for (40 – x) days.
   =15 (40 – x) – 5x =160|
   600-15x-5x=160
   20x=600-160
   20x=440
   x = 22.
9. The ratio between the length and the breadth of a rectangular park is 4 : 1. If a man cycling along the boundary of the park at the speed of 15 km/hr completes one round in 10 minutes, then the length of the park (in sq. m) is:
   A) 850
   B) 1000
   C) 600
   D) 560
   E) None
   
   View Answer

   Option B
   Solution:
   Perimeter = Distance covered in 10 min.
   =(15000/60)*10 =2500m
   Let h = 4x and b = x
   Then, 2(4x + x) = 2500
   x = 250.
   then l=4*250 =1000.
10. An error 3% in excess is made while measuring the side of a square. The percentage of error in the calculated area of the square is:
    A) 5.45%
    B) 5.10%
    C) 6.09%
    D) 4.5%
    E) None
    
    View Answer

    Option C
    Solution:
    Let 100 cm is read as 103 cm.
    Area 100*100=10000
    Error area 103*103=10609
    Diff=609.
    %ge error=(609/10000)*100 =6.09%.

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