static void Main(string[] args) { BookDB bookDB = new BookDB(); AddBooks(bookDB); PriceTotaller totaller = new PriceTotaller(); bookDB.ProcessPaperbackBooks(new ProcessBookDelegate(PrintTitle)); bookDB.ProcessPaperbackBooks(new ProcessBookDelegate(totaller.AddBookToTotal)); Console.WriteLine("Average Paperback Book Price: ${0:#.##}", totaller.AveragePrice()); Console.ReadLine(); //Output //Paperback Book Titles: //The C Programming Language //The Unicode Standard 2.0 //Dogbert's Clues for the Clueless //Average Paperback Book Price: $23.97 }