Task: Question Answering
Input (English): Problem: 81 men working 8 hours per day dig 30 m deep . how many extra men should be put to dig to a depth of 50 m working 6 hours per day ? 
Options: a ) a ) 99 , b ) b ) 77 , c ) c ) 66 , d ) d ) 55 , e ) e ) 88
Output (English): a