Task: Question Answering
Input (English): Problem: solution a is made up of alcohol and water mixed in the ratio of 21 : 4 by volume ; solution b is made up of alcohol and water mixed in the ratio of 2 : 3 by volume . if solution a and solution b are mixed in the ratio of 5 : 6 by volume , what percent of the resultant mixture is alcohol ? 
Options: a ) 32.5 % , b ) 40 % , c ) 60 % , d ) 65 % , e ) can not be determined
Output (English): c