4. Case Study:
Sumeet works at a book shop. Sumeet loves to spend time with books and enjoy arranging books in shelves according to its categeory While arranging some books on the book shelf, he observed that there are 5 History books, 3 Mathematics books and 4 Science books which are to be arranged on the shelf. He always try to arrange in best possible method so that every reader can easily find book according to subject to save time.
(i) Find the number of ways if he the books of same subject are put together in a shelf.
ii)Find the number of arrangements if he select 3 History books 2 Maths books and 2 Science books
