In a vessel, there are 10 litres of alcohol. An operation is defined as taking out five litres of what is present in the vessel and adding 10 litres of pure water to it. What is the ratio of alcohol to water after two operations? Choose the most appropriate option.
A) 1 : 0	B) 1 : 5	C) 1 : 1	D) 1 : 2	E) 1 : 9
Final concentration = Initial concentration (1−replacement quantityfinal volume)(1−replacement quantityfinal volume)   Final concentration = =1×(1−1015)=13=1×(1−1015)=13   Final concentration = 13×(1−1020)=1613×(1−1020)=16   So ratio of alcohol : water = 1 : 5   Answer:1 : 5
<result>B</result>
In a vessel, there are 10 litres of alcohol. An operation is defined as taking out five litres of what is present in the vessel and adding 10 litres of pure water to it. What is the ratio of alcohol to water after two operations?