Task: Question Answering
Input (English): Problem: 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 ? 
Options: a ) 7 % , b ) 10 % , c ) 13 % , d ) 16 % , e ) 19 %
Output (English): c