How many liters of water must be added to 18 liters of milk and water containing 10% water to make it 40% water?	Pick one:
A) 6 B) 7 C) 8 D) 9 E) 10
By rule of alligation:   40% - 10% = 30%   100% - 40% 40  - 10= 
<gadget id="calculator">40  - 10</gadget>
<output>30</output>
30%   100% - 40% = 60%   Quantity of pure water : Quantity of the mixture  100  - 40= 
<gadget id="calculator"> 100  - 40</gadget>
<output>60</output>
60%   Quantity of pure water : Quantity of the mixture= 1 : 2   There are 18 liters of mixture, so we need to add 9 liters of pure water.   The answer is 9.
<result>D</result>
How many liters of water must be added to 18 liters of milk and water containing 10% water to make it 40% water?