Exercise :: Alligation or Mixture  General Questions
 Alligation or Mixture  Important Formulas
 Alligation or Mixture  General Questions
6.  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: 

Answer: Option C Explanation: Let C.P. of 1 litre milk be Re. 1 Then, S.P. of 1 litre of mixture = Re. 1, Gain = 25%.
By the rule of alligation, we have:

7.  How many kilogram of sugar costing Rs. 9 per kg must be mixed with 27 kg of sugar costing Rs. 7 per kg so that there may be a gain of 10% by selling the mixture at Rs. 9.24 per kg? 

Answer: Option D Explanation: S.P. of 1 kg of mixture = Rs. 9.24, Gain 10%.
By the rule of allilation, we have:
Ratio of quantities of 1^{st} and 2^{nd} kind = 14 : 6 = 7 : 3. Let x kg of sugar of 1^{st} be mixed with 27 kg of 2^{nd} kind. Then, 7 : 3 = x : 27

8.  A container contains 40 litres of milk. From this container 4 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? 

Answer: Option D Explanation:

9.  A jar full of whisky contains 40% alcohol. A part of this whisky is replaced by another containing 19% alcohol and now the percentage of alcohol was found to be 26%. The quantity of whisky replaced is: 

Answer: Option B Explanation: By the rule of alligation, we have:
So, ratio of 1^{st} and 2^{nd} quantities = 7 : 14 = 1 : 2

10.  In what ratio must water be mixed with milk to gain 16% on selling the mixture at cost price? 

Answer: Option A Explanation: Let C.P. of 1 litre milk be Re. 1.
By the rule of alligation, we have:
