Answer :
Really all you have to do is divide the battery life by the movie lengths. Calculator time!
(4 & 1/3) / (1 & 2/3) = (2 & 2/3)
You can watch 2 & 2/3 movies with your battery life.
(4 & 1/3) / (1 & 2/3) = (2 & 2/3)
You can watch 2 & 2/3 movies with your battery life.