A 40-liter solution of alcohol and water is 5 percent alcohol. If 4.5 liters of alcohol and 5.5 liters of water are added to this solution, what percent of the solution produced is alcohol?
Choose the correct choice from the following answers
A) 7 %
B) 10 %
C) 13 %
D) 16 %
E) 19 %

Rationale: the percent of alcohol in the solution is ( 0.05 ( 40 ) + 4.5 ) / 50 = 6.5 / 50 = 13 % the answer is c .
Answer: C