Quantitative Aptitude: Mixture and Alligation Questions Set 3

Mixture Alligation Questions NIACL. SBI PO, IBPS PO, NICL, RBI Grade B, Dena Bank PO PGDBF, BOI, Bank of Baroda and other competitive exams

1. A container contains 80 Litre milk. From this container 8 Litre milk was taken out and replaced with water. This process was further repeated two times. How much milk is now contained in the container?
   A) 58.32 L
   B) 57.32 L
   C) 59.32 L
   D) 56.32 L
   E) 55.32 L
   
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   Option A
   Solution:
   Remaining Quantity= x*(1-y/x)^n
   where x= quantity of initial liquid=80 here;
   y= quantity of newly added liquid=8 here
   n= number of times the process is repeated= 3 here
   80*(1-8/80)^3 = 58.32 L
2. A trader sold two articles in Rs 800. On one he gained 33(1/3)% and on another he gained 20%. In this whole transaction he gained 25%. Find the cost price of the second article (the one sold at 20% gain)
   A) Rs 240
   B) Rs 400
   C) Rs 300
   D) Rs 500
   E) Rs 550
   
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   Option B
   Solution:
   At 25% profit and SP=800; CP=640
   33(1/3)                           20
   .                    25
   5                                    25/3
   3:5 (by alligation)
   hence CP od second article=5/8*640=400
   
3. A mixture of certain quantity of milk with 20 Litre of water is sold at 80 paise per litre. If pure milk be worth Rs 1.20 per litre. How much milk is present in the mixture?
   A) 20 L
   B) 25 L
   C) 30 L
   D) 40 L
   E) 35 L
   
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   Option D
   Solution: By alligation
   120                            0
   .                  80
   80                            40
   =>2:1
   1=20 L
   hence 2=40 L
4. In an alloy, zinc and copper are in the ratio 1:3. In the second alloy the same elements are in the ratio 2:3. If what proportion should the two alloys be mixed so as to form a new alloy in which zinc and copper are in the ratio 1:2.
   A) 5:4
   B) 4:5
   C) 5:6
   D) 6:5
   E) 2:3
   
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   Option B
   Solution:
   1/4                 2/5
   .            1/3
   1/15               1/12
   =>4:5
5. 400 grams of sugar solution has 40% sugar in it. How much sugar should be added to make it 50% in the solution?
   A) 60 gm
   B) 70 gm
   C) 80 gm
   D) 90 gm
   E) 160 gm
   
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   Option C
   Solution:
   40% of 400= 160 gm
   remaining=240. This remaining quantity will remain constant as only sugar is to be added. For sugar to be 50% , the quantity of sugar should be equal to 240
   hence more to be added=240-160=80
6. A dishonest milkman professes to sell his milk at cost price, but he mixes it with water and thereby gains 33(1/3)%. The percentage of water in the mixture is?
   A) 20%
   B) 33 (1/3) %
   C) 25%
   D) 30%
   E) 35%
   
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   Option C
   Solution:
   Ratio of water : milk can be found out as
   Water: Milk=33(1/3):100 =1:3
   hence water = 1/(1+4)*100=25%
7. A person has a chemical of Rs 15 per litre. In what ratio should water be mixed in that chemical so that after selling the mixture at Rs 12/litre he may get a profit of 20%.
   A) 1:2
   B) 2:1
   C) 1:3
   D) 3:1
   E) 3:2
   
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   Option B
   Solution: With 20% profit, and SP=12, CP=10
   By alligation,
   15                    0
   10
   10                    5
   =>2:1
8. If 2 kg of metal, of which 1/3 is zinc and the rest is copper be mixed with 3 kg of metal of which ¼ is zinc and the rest is copper, What is the ratio of zinc to copper in the mixture?
   A) 2:3
   B) 3:2
   C) 43:17
   D) 17:43
   E) 15:17
   
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   Option D
   Solution:
   Zinc=2*1/3 + 3*1/4=17/12
   Copper=5-17/12=43/12
   hence Z:C=17:43
9. A man has 90 pens. He sells some of these at a profit of 15% and the rest at 9% profit. On the whole transaction he gets a profit of 11%. How many pens did he sell at 9% profit?
   A) 60
   B) 50
   C) 40
   D) 70
   E) 30
   
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   Option A
   Solution:
   15                            9
   .              11
   2                             4
   => 1 : 2
   hence pen at 9% profit= 2/3*90=60
10. A butler stole wine from a butt of sherry which contained 35% spirit and he replaced what he had stolen by wine containing only 20% spirit. The butt was then 25% strong only. How much of the butt did he steal?
    A) 1/3
    B) 2/3
    C) 3/4
    D) 1/4
    E) 1/2
    
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    Option B
    Solution:
    35%                         20%
    25%
    5                               10
    =>1:2
    The butt with alcohol of 35%=1/3 means butler stole 1-1/3=2/3 part