Task: Question Answering
Input (English): Problem: if 20 liters of chemical x are added to 80 liters of a mixture that is 15 % chemical x and 85 % chemical y , then what percentage of the resulting mixture is chemical x ? 
Options: a ) 30 % , b ) 32 % , c ) 35 % , d ) 38 % , e ) 40 %
Output (English): b