gráfica del costo y la demanda de usuarios de los Sistemas Operativos que se están usando en la actualidad.​

1)consider the following code snippet: #ifndef book_h#define book_hconst double max_cost = 1000.0; class book{public: book(); book(double new_cost); void set_cost(double new_cost); double get_cost() const; private: double cost; }; double calculate_terms(book bk); #endifwhich of the following is correct? a)the header file is correct as given. b)the definition of max_cost should be removed since header files should not contain constants. c)the definition of book should be removed since header files should not contain class definitions. d)the body of the calculate_terms function should be added to the header file.

Laire writes a letter to her grandmother, in which she describes an amusement park she visited last week. she adds pictures of that place in her letter. which feature of a word processing program will claire to remove unwanted parts of the pictures?

Peter is thinking of a number which isless than 50. the number has 9 factors. when he adds 4 to the number, itbecomes a multiple of 5. what is thenumber he is thinking of ?