Answer:
<em>There are 1700 books in the library.</em>
Step-by-step explanation:
<em>If 28% of the books is non-fiction, that means the remaining 72% of books are fiction.</em>
If 72% of the books are fiction, 1224/72 will give us 1%, which is 17.
If 1% is 17 books, then 17*100=100% of books.
There are 1700 books in the library.
Spider-Man 120
Superman 40