Task: Question Answering
Input (English): Problem: a is thrice as good a work man as b and together they finish a piece of work in 12 days . the number of days taken by a alone to finish the work is : 
Options: a ) 28 days . , b ) 14 days . , c ) 12 days . , d ) 16 days . , e ) 18 days .
Output (English): d