Sean read 1/5 of a book in 1 1/2 hours. How long will it take Sean to read 1/2 of this book?

3 hours and 45 mins, because multiply it by 2 and there is 3 hours. he has read 2/5 of the book, now you need to add. 5 to this. divide how long it took him to read 1/5 by 2 and add that to your number. 3 hours and 45 mins