Task: Question Answering
Input (English): Problem: a contractor undertakes to complete the construction of a tunnel 720 meters long in 240 days and employs 50 men for the purpose . after 120 days , he finds that only 240 meters of the tunnel is complete . how many more men should be employ in order to complete the work in time ? 
Options: a ) 75 men , b ) 80 men , c ) 70 men , d ) 60 men , e ) 50 men
Output (English): c