###Human: The time Juan takes to grab his lunch from his office and back is half the time he takes to read a book. If he has a 4000-page book, how many pages does he read in an hour if he takes 4 hours to move from his office to grab lunch?, ### Assistant: If Juan takes 4 hours to move from his office to grab lunch, moving from his office and back takes 2*4=8 hours.
The time Juan takes to grab his lunch from his office and back is half the time he takes to read a book, meaning he reads a book in 8*2=16 hours.
If he has a 4000-page book, he will read 4000/16=250 pages in an hour. 
 So the answer is :  250