How many liters of pure alcohol must be added to a 100-liter solution that is 20 percent alcohol in order to produce a solution that is 35 percent alcohol?  Choose the correct answer:
A) 7/2  B) 300/13  C) 20/3  D) 8  E) 39/4
20% Alcohol solution means; in the 100 liter solution, 20 liters of solution is alcohol and 80 liters other solvents.   If we addxliters of alcohol to the solution, the solution becomes100+xliters and alcohol, which was 20 liters, becomes 20+x liters.   According to the statement;   20+x = 35% of (100+x)   OR   20+x=(100+x)7/20   400+20x=700+7x   13x=300   x=300/13   Ans:300/13
<result>B</result>
How many liters of pure alcohol must be added to a 100-liter solution that is 20 percent alcohol in order to produce a solution that is 35 percent alcohol?