Alligation and Mixture Aptitude Test Paper 1
1) A 60 liter mixture of milk and water contains 10% water. How much water must be added to make water 20% in the mixture?
- 8 liters
- 7.5 liters
- 7 liters
- 6.5 liters
The Correct answer is (B)
Answer with explanation:
The mixture has 10% water, so the milk would be 90% of 60 liters.
Milk = 
* 60 = 54 liters
            100       Â
∴Water = 60 – 54 = 6 liters
Let water to be added = x liters
Now,   6+x  * 100 = 20
           60+x      Â
  6+x  =    1 Â
  60+x      5 Â
30 + 5x = 60+x
30 – 60 = x – 5x
– 30 = – 4x
x =30Â Â =7.5 liters
      4    Â
2) An alloy contains14 parts of tin and 100 parts of copper. What is the percentage of tin in the alloy ?
- 12.3%
- 13%
- 11.5%
- 11%
The Correct answer is (A)
Answer with explanation:
In 114 parts of alloy, tin = 14 parts
∴Percentage of tin =  14  ∗100=12.3%
                              114       Â
3) A 20 liter mixture contains 30% alcohol and 70% water. If 5 liters of water is added to the mixture, what will be the percentage of alcohol in the new mixture ?
- 22%
- 23%
- 24%
- 25%
The Correct answer is (C)
Answer with explanation:
Initially, the mixture contains 30% alcohol =  30 ∗20=6 liters of alchol
                                                                  100       Â
And, 70% of water =  70 ∗20=14 liters of water
                                100       Â
After adding 5 liters of water, the mixture contains (14+5) 19 liters of water and 6 liters of alcohol.
∴Percentage of alcohol = 6 ∗100=24%
                                    25
4) In what ratio water must be mixed with milk costing Rs. 48 per liter to get a mixture worth Rs. 32 per liter ?
- 2:3
- 3:2
- 3:4
- 1:2
The Correct answer is (D)
Answer with explanation:
Apply alligation rule:
∴ Water = 16 = 1
    Milk     32    2Â
Required ratio; water:milk = 1:2
5) A shopkeeper mixes 60 kg of sugar worth Rs. 30 per kg with 90 kg of sugar worth Rs. 40 per kg. At what rate he must sell the mixture to gain 20%?
- Rs. 30 per kg
- Rs. 34 per kg
- Rs. 43.2 per kg
- Rs. 38 per kg
The Correct answer is (C)
Answer with explanation:
Total cost price of (60+90)150 kg of mixture = (60*30+90*40)
                                                                       = 1800+3600
                                                                       = Rs. 5400
Cost Price per kg of mixture = 5400 = Rs. 36 per kg
                                              150
Now, Required gain = 20%
∴Required selling price per kg of mixture = 120 ∗36 = Rs. 43.2 per kg
                                                                100
Alligation and Mixture Aptitude Test Paper 2 Alligation and Mixture Concepts