Mixed Quantitative Aptitude Questions Set 41

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 pipe can fill a tankin 12 minutes and another pipe in 15 minutes, but a third pipe can empty it in 6 minutes. The first two pipes are kept open for 5 minutes in the beginning and then the third pipe is also opened. In what time is the cistern emptied?
   A) 35mins.
   B) 50 mins.
   C) 45 mins.
   D) 42 mins.
   E) 30 mins.
   
   View Answer

     Option C
   Solution:
   Net work done by 3 pipes in minute = [(1/12) + (1/15) –(1/6)] = -(1/60)
   -ve sign shows that (1/60) part is emptied in 1 minutes
   Therefore,
   (3/4) part is emptied in 60*(3/4) = 45 min.
   
2. The speeds of two trains are in the ratio of 7:9. They are moving in the opposite directions on parallel tracks . The first train crossed a telegraph pole in 4 seconds whereas the second train crossed the same pole in 6 seconds. Find the time taken by the trains to cross each other completely.
   A) 9(1/2)
   B) 7(1/4)
   C) 8(1/3)
   D)5(1/5)
   E) 5(1/8)
   
   View Answer

     Option E
   Solution:
   Length of both trains = (7*4) + (9*6) = 28 + 54 = 82 m
   Time = D/speed
   => 82 /(7+9) = 5(1/8) sec.
   
3. Starting from his house one day, a student walks at a speed of 2(1/2) km/hr and reaches his school 6 minutes late. Next day at the same time he increases his speed by 1 km/hr and reaches the school 6 minutes early. How far is the school from his house?
   A) 1(4/3) km
   B) 1(3/4) km
   C) 2(1/3) km
   D) 5(1/2) km
   E) 3(1/3) km
   
   View Answer

     Option B
   Solution:
   Required distance = [speed multiplied /diff. of speed ]*diff. in time
   = [2(1/2)*3(1/2)]/[3(1/2) – 2(1/2)] *[(6+6)/60] =7/4 = 1(3/4) km.
   
4. A dishonest milkman professes to sell his milk at cost price but he mixes it with water and thereby gains 25%. What is the percentage of water in the mixture.
   A) 20%
   B) 18%
   C) 22%
   D) 29%
   E) 35%
   
   View Answer

     Option
   Solution:
   Let CP of milk be Rs. 1 per litre.
   Then, the SP of litre of mixture = Rs. 1
   gain =25%
   CP of 1litre of mixture = (100/125) = 4/5
   Quantity of water / Quantity of milk = (1/5)/(4/5) = (1/4)
   CP of 1 litre of water ————————-CP of 1 litre of milk
   0 …………………………………………………………..Rs. 1
   mean price = (4/5)
   (1/5)     :                                        (4/5)
   Required Proportion = 1:4
   % of water = 4/(1+4) *100 = 20%
   
5. Three typists A, B and C have to type 836 pages. A types one page in 5 minutes, B in 15 minutes and C in 20 minutes. In what time will these pages be typed if they work together?
   A) 44 hrs.
   B) 35 hrs.
   C) 48hrs.
   D) 32hrs.
   E) 28 hrs.
   
   View Answer

     Option
   Solution:
   1/5 + 1/15 + 1/20 = 19/60
   Time taken = 836*(60/19) = 44*60 = 2640 minutes = 44 hours
6. The total marks obtained by a student in Physics, Chemistry and Mathematics together is 120 more than the marks obtained by him in Chemistry. What are the average marks obtained by him in Physics and Mathematics together?
   A) 62
   B) 55
   C) 47
   D) 60
   E) 58
   
   View Answer

     Option D
   Solution:
   P + C + M = 120 + C
   => P + M = 120
   Average = 120/2 = 60
   
7. The income of a broker remains unchanged though the rate of commission is increased from 4 per cent to 5 per cent. Find the percentage of slump in business.
   A) 15%
   B) 20%
   C) 22%
   D) 18%
   E) 17%
   
   View Answer

     Option B
   Solution:
   Let the business value changes from Rs. x to Rs.y
   Therefore ,
   4% of x =  5% of y
   => y = (4/5)x
   Change in business = (x – (4/5)x) = x/5
   Then, Percentage slump in business = (x/5)*(1/x)*100 = 20%
   
8. Ram derive an annual income of Rs.688.25 from Rs.10000 invested partly at 8% per annum and partly at 5% per annum simple interest. How many of my money is invested at 5%?
   A) Rs.5240
   B) Rs.2290
   C) Rs.3254
   D) Rs.4500
   E) Rs.3725
   
   View Answer

     Option E
   Solution:
   Let the money invested at 5% be Rs.x .
   Now,
   (x*1*5)/100 + [(10000-x)*1*8]/100 = 688.25
   => 5x – 8x + 80000 = 688.25
   => 3x = 11175
   => x = Rs.3725
9. There are 9 red, 7 white and 4 black balls in an urn. Two balls are drawn at random from the urn. What will be the probability that both the balls are red?
   A) 18/95
   B) 19/99
   C) 17/100
   D) 18/75
   E) 19/110
   
   View Answer

     Option A
   Solution:
   Total possible outcome = 20C2 = 190
   Favorable outcomes = 9C2 = 36
   Required Probability = 36/190 = 18/95
   
10. In how many ways can a student choose a programme of 5 courses, if 10 courses are available and 2 courses are compulsory for every student?
    A) 55
    B) 60
    C) 56
    D) 48
    E) 62
    
    View Answer

      Option C
    Solution:
    Required no. of ways = 8C3 = 56 ways
    

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