Quantitative Aptitude: Mixture and Alligation Questions Set 10

Mixture and Alligation Questions for IBPS RRB, SBI PO, IBPS PO/Clerk, RBI, UICC, OICL, BOI, Bank of Baroda and other competitive exams

1. A vessel is filled with liquid, which is 3 parts water and 5 parts milk. How much of the liquid should be drawn of and replaced by water to make it half water and half milk?
   A) 1/8
   B) 1/5
   C) 2/3
   D) 2/7
   E) None
   
   View Answer

   Option B
   Solution:
   Suppose the vessel initially contains 8 litres of liquid.
   Let x litres of this liquid be replaced with water.
   water in new mixture =(3-3x/8+x)
   syrup in new mixture =(5-5x/8)
   Then (3-3x/8+x) = (5-5x/8)
   5x + 24 = 40 – 5x
   10x=16==>x=8/5
   So part of mixture replaced is 8/5*1/8=1/5
   
2. Milk and water are in a Can A as 4:1 and in Can B as 3:2. For Can C, if one takes equal quantities from A and B, find the ratio of milk to water in C.
   A) 7:3
   B) 4:7
   C) 3:5
   D) 5:4
   E) None
   
   View Answer

   Option A
   Solution:
   Ratio of only milk in vessel A = 4 : 5
   Ratio of only milk in vessel B = 3 : 5
   Let ‘x’ be the quantity of milk in vessel C
   4/5………………….3/5
   ……………x
   3/5-x………………x – 4/5
   (3/5-x)/(x-4/5)=1/1
   X=7/10
   Therefore, quantity of milk in vessel C = 7
   => Water quantity = 10 – 7 = 3
   Hence the ratio of milk & water in vessel 3 is 7 : 3
3. A mixture contains alcohol and water in the ratio 3:2. If it contains 3 liters more alcohol than water, then what is the quantity of alcohol in the mixture?
   A) 6
   B) 8
   C) 9
   D) 5
   E) None
   
   View Answer

   Option C
   Solution:
   If quantity of water as x and alcohol as x+3.
   (x+3)/x=3/2
   Water x=6 and alcohol = x+3 = 9 liters
   
4. Three types of Rice of Rs. 1.27, Rs. 1.29 and Rs. 1.32 per kg are mixed together to be sold at Rs. 1.30 per kg. In what ratio should this rice be mixed?
   A) 4:1:3
   B) 2:3:1
   C) 1:1:2
   D) 1:2:1
   E) None
   
   View Answer

   Option C
   Solution:
   127………………………..132
   ………………130
   2…………………………….3
   Then
   129………………132
   ………….130
   2…………………….1
   Hence final ratio is 2 :  2:  (3+1) ==>1:1:2
   
5. A dishonest milkman professes to sell his milk at cost price but he mixes it with water and thereby gains 25%. The percentage of water in the mixture is:
   A) 35%
   B) 15%
   C) 25%
   D) 20%
   E) None
   
   View Answer

   Option D
   Solution:
   Let CP of 1 litre milk be Rs 1
   Then SP of 1 litre of mixture =Rs 1 Gain 25%
   CP of 1 litre mixture =Rs (100/125*1)=4/5
   Milk………………..Water
   1………………………0
   …………..4/5
   4/5……………………1/5
   Ratio 4:1
   Hence %ge of water in the mixture =(1/5*100)=20%
   
6. A container contains 50 litres of milk. From this container 5 litres of milk was taken out and replaced by water. This process was repeated further two times. How much milk is now contained by the container?
   A) 28.50
   B) 36.45
   C) 25.5
   D) 32.25
   E) None
   
   View Answer

   Option B
   Solution:
   Amount of milk left after 3 operations ={50 (1-5/50)³}
   =50 * 9/10 * 9/10 * 9/10
   =36.45
   
7. An alloy of gold and copper weights 50 g. It contains 80% gold. How much gold should be added to the alloy so that percentage of gold is increased to 90?
   A) 50gm
   B) 60gm
   C) 45gm
   D) 35gm
   E) None
   
   View Answer

   Option A
   Solution:
   Gold in alloy =50*80% =40gm
   Copper in alloy =50*20%=10gm
   Now,
   (40+x)/10=90/10
   X=50gm
   
8. A trader sells total 315 TV sets. He sells black and white TV sets at a loss of 6% and color TV sets at a profit of 15% thus he gains 9% on the whole. What are the no. of black and white sets which he has sold?
   A) 100
   B) 105
   C) 90
   D) 85
   E) None
   
   View Answer

   Option C
   Solution:
   -6………………..+15
   …………..9
   6………………………15
   2……………………..5
   7  == 315
   2 ? == 90
   => x=90
9. 9. 4 kg of a metal contains 1/5 copper and rest in Zinc. Another 5 kg of metal contains 1/6 copper and rest in Zinc.The ratio of Copper and Zinc into the mixture of these two metals:
   A) 54:181
   B) 39:231
   C) 62:121
   D) 49 : 221
   E) None
   
   View Answer

   Option D
   Solution:
   Copper in 4 kg = 4/5 and Zinc in 4 kg = 4*4/5=16/5
   Copper in 5 kg = 5/6 and Zinc in 5 kg = 5*5/6=25/6
   Therefore, Copper in mixture = 4/5 + 5/6=49/30
   and Zinc in the mixture = 16/5 + 25/6=221/30
   Therefore the required ratio = 49 : 221
   
10. Rs. 69 were divided among 115 students so that each girl gets 50 paise less than a boy. Thus each boy received twice the paise as each girl received. The no. of girls in the class is:
    A) 47
    B) 23
    C) 92
    D) 25
    E) None
    
    View Answer

    Option C
    Solution:
    Here each girl receives 50 paise and each boy receives 100 paise and the average receiving of each student.
    =6900/115=60paise
    50…………………….100
    …………..60
    40……………………..10
    4:1
    5 == 115
    4 ? == 92

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