Two books are compulsory, so the student really wants to know how many ways he can pick 3 out of 7. That is 35.
The average number of books read by a student is 2-3 books a month. This all depends on how big of a reader the student is and how many books are they reading in classes.
93
700
Socrates' student, Plato, wrote many books to spread his teachings.
You can wind up with 10 different pairs of books in your hand, which you can choose from a shelf of 5 books in 20 different ways.
In the Bible, God choose certain people to write 66 books.
360
This is 6! {factorial} = 6 x 5 x 4 x 3 x 2 x 1 = 720. The way this works: take student A, who can choose any of the 6 desks, then for each of those 6 choices that student A makes, student B has 5 desks to choose from, after that choice has been made, student C has 4 desks to choose from, ... until the last student has only one to choose from.
Try your local library, they have many books about the subject.
792 different groups of 5 books, in 95,040 different sequences.
It depends on which edition you choose. Most books have page numbers written on them. You would know this if you read books.
There are many different books that can help you choose a career. Some books are "Job Hunting & Careers," "Early Career Books" and "100 Conversations for Career Success: Learn to Network, Cold Call, and Tweet Your Way to Your Dream Job!"