The Greenville Public Library just received a grant to renovate their children's reading room. Before any work begins, the librarians need to pack all of their picture books into cardboard boxes to keep them safe. They estimate that each book weighs an average of 12 ounces. To make sure the boxes are not too heavy, they only plan to put 15 pounds of books in each box. If the library has 1,200 picture books, how many boxes do the librarians expect to need?