Task: Question Answering
Input (English): Problem: if 20 liters of chemical x are added to 80 liters of a mixture that is 5 % chemical x and 95 % chemical y , then what percentage of the resulting mixture is chemical x ? 
Options: a ) 24 % , b ) 26 % , c ) 28 % , d ) 30 % , e ) 32 %
Output (English): a