3! (4! X 6! X 2!)
There are n! ways of arranging n objects. So we get, for example, 6! ways of organising the physics books. But we multiply but 3! because there are 3 catagories of books and so 3! ways of ordering these catagories.
3! (4! X 6! X 2!)
There are n! ways of arranging n objects. So we get, for example, 6! ways of organising the physics books. But we multiply but 3! because there are 3 catagories of books and so 3! ways of ordering these catagories.