Quantitative Aptitude: Ratio and Proportion Questions Set 2

Quantitative Aptitude Questions for SBI PO, IBPS PO/Clerk, OICL, NIACL, NICL, LIC, BOI, Bank of Baroda and other competitive exams.

1. The number of students in 3 classes is in the ratio 6:7:8. If 15 students are increased in each class this ratio changes to 9:10:11. The total number of students in the three classes in the beginning was
   A) 84
   B) 105
   C) 126
   D) 168
   E) None
   
   View Answer

   Option B
   Solution:
   Let the number of students in the classes be 6x, 7x and 8x respectively;
   Total students = 6x+7x+8x = 21x.
   Then (6x+15)/(7x+15)=9/10
   60x+150=63x+135
   X=5.
   Total students =21*5=105.
2. A and B are two alloys in which ratios of Zinc and Sulphur are 4:5 and 6:7 respectively. If these equally amount of two alloys are melted and made alloy C. What will be the ratio of Zinc and Sulphur in alloy C?
   A) 27:32
   B) 32:27
   C) 15:22
   D) 22:15
   E) None
   
   View Answer

   Option E
   Solution:
   Zinc in Alloy A=4/9
   Zinc in Alloy B=6/13
   Sulphur in Alloy A=5/9
   Sulphur in Alloy B=7/13
   Then in alloy C Zinc : Sulphur
   4/9+6/13 : 5/9+7/13
   106/117: 128/117
   =53:64.
3. If 5/8th of a cistern is filled in 1 minutes, how much more time will be required to fill the rest of it.
   A) 25sec
   B) 20sec
   C) 45sec
   D) 36sec
   E) None
   
   View Answer

   Option D
   Solution:
   5/8 part filled in 1 minute
   full filled in 8/5 minute
   so remaining 3/8 will filled in (8/5)*(3/8) = 3/5 minute = 36 seconds .
4. A dishonest milk man mixed 1 liter of water for every 3 liters of milk and thus made up 36 liters of milk. If he now adds 15 liters of milk to mixture, find the ratio of milk and water in the new mixture:
   A) 13:5
   B) 14:3
   C) 3:14
   D) 5:13
   E) None
   
   View Answer

   Option B
   Solution:
   Quantity of milk and water in the 36 liter mixture;
   27 liter milk and 9 liter water.
   Now, 15 liters milk is added then milk becomes 42 liters.
   Now, ratio = 42:9 = 14:3.
5. The ratio between the ages of P and Q is 3:2 respectively. If the ratio between 1/5th of P’s age and 1/3rd of Q’s age is 9:10. Find the age of Q
   A) 45
   B) 30
   C) 32
   D) Data Inadequate
   E) None
   
   View Answer

   Option D
   Solution:
   Data Inadequate.
6. A bucket contains a mixture of two liquids A & B in the proportion 5 : 3. If 16 litres of the mixture is replaced by 16 litres of liquid B, then the ratio of the two liquids becomes 3 : 5. How much of the liquid B was there in the bucket?
   A) 16.5 l
   B) 18 l
   C) 14.5 l
   D) 15 l
   E) None
   
   View Answer

   Option D
   Solution:
   Let bucket contains 5x and 3x of liquids A and B respectively.
   When 16 litres of mixture is replaced, A and B has a mixture is
   [5x – (5/8)*16] = (5x – 10)
   [3x – (3/8)*16] = (3x – 6)
   Ratio (5x – 10)/(3x – 6+16) = 3/5
   (5x – 10)/(3x +10) = 3/5
   X=5.
   So, quantity of liquid B initially,
   = 3*5 = 15 litres.
   
7. The difference between two positive numbers is 10 and the ratio between them is 5:3. Find the product the two numbers
   A) 360
   B) 375
   C) 390
   D) 425
   E) None
   
   View Answer

   Option B
   Solution:
   Let the two positive numbers be 5x and 3x respectively.
   5x-3x = 10
   x = 5.
   Then numbers are 25 and 15.
   Thus, their product = 25*15 = 375.
8. If the ratio of the ages of Guna and Shekar is 6:7 at present, and twelve years from now, the ratio will get changed to 8:9, then find Guna’s present age.
   A) 38
   B) 46
   C) 42
   D) 36
   E) None
   
   View Answer

   Option D
   Solution:
   Let Guna’s and Shekar’s present age is 6x and 5x respectively.
   then
   (6x+12)/(7x+12) = 8/9
   54x+108 = 56x + 96
   2x = 12
   x = 6
   Present age of Guna = 6x = 36.
9. The ratio of Elephant and Deer in the zoo is 43 : 47 respectively. The average number of Elephant and Deer in the zoo is 135. What is the number of Deer in the pond ?
   A) 166
   B) 135
   C) 141
   D) 156
   E) None
   
   View Answer

   Option C
   Solution:
   Ratio 43:47
   Average 135
   Then Total=2*135=270.
   Deer=270*47/90
   =141.
10. The ratio of male and female in a city is 7 : 8 respectively and percentage of children among male and female is 25 and 20 respectively. If number of adult females is 156800, what is the total population of the city?
    A) 400000
    B) 386400
    C) 367500
    D) 412300
    E) None
    
    View Answer

    Option C
    Solution:
    Let the total population be ‘p’
    Male :Female 7 : 8
    Percentage of children among male and female is 25% and 20%
    Then Adults male and female % = 75% & 80%
    => 80%(8p/15) = 156800
    => 80 x 8p/15 x 100 = 156800
    => p = 156800 x 15 x 100/80 x 8
    => p = 367500
    Therefore, the total population of the city = p = 367500.