Question 77004
 so after school the remaining work will be =>  1- 1/3 = 2/3

 He did 1/4 of the remining work before dinner 
  So remaing part will be  1-1/4 = 3/4   
         which equals to => 2/3 x 3/4 of whole the part
                           = 1/2

So he must do 1/2 of his home work after dinner.