Problem: a contractor undertakes to do a job within 100 days and hires 10 people to do it . after 20 days , he realizes that one fourth of the work is done so he fires 2 people . in how many more days g will the work get over ? 
Options: a ) 60 , b ) 70 , c ) g = 75 , d ) g = 80 , e ) 100
c