b) Imagine a publishing company that markets both book and audiocassette version to its works. Create a class publication that stores the title (a string) and price (type float) of a publication. From this class derive two classes: book, which adds a page count (type int); and tape, which adds a playing time in minutes (type float). Each of these three classes should have a getdata( ) function to gets its data from the user at the keyboard, and a putdata( ) function to display its data. Write a main( ) program in C++ to test the book and tape classes by creating instances of them, asking the user to fill in data with getdata( ), and than displaying the data with putdata( ).