Task: Question Answering
Input (English): Problem: the width of a rectangular hall is ½ of its length . if the area of the hall is 200 sq . m , what is the difference between its length and breadth ? 
Options: ['a ) 8 m', 'b ) 10 m', 'c ) 12 m', 'd ) 15 m', 'e ) 17 m']
Output (English): b