Question

15 leter mixture contains 20% alcohol and remaining is water. If 3 liters water is mixed in that mixture, then what will be the percentage of alcohol in the new mixture? Short trick

Answer 1

In 15 litre solution percentage of alcohol is 20%

Amount of alcohol precent in solution is: 15*20/100

= 3 litre.

Now,

        3 litre water is added.

New volume of solution = 18 litre.

Volume of alcohol in Solution = 3 litre.

Percentage of alcohol in solution is (3/18)*100 = 16.66 %