Implementation: Office Exam in C# windowsForm

i have to implement a MicrosoftOffice Exam(windows forms and completely Local). i have 3 tables(user,question,mark). users Submit in exam and start(user information added to user table). a random questions will appear to user. questions are like: 1) dear user, you have a word document in desktop, there is a sentence in and you must apply size:24,color:red to this sentence. 2) you have an excel document, you must calculate average in cell c12 ------ my problem is about how can i realize the answer is correct and user completely do them(the way he do, isn't important, just final result is important).

my problem just is about how can i realize the result is true. forexample, a question: create a directory in desktop. i can realize it from this code:

      if (Directory.Exists(Path.Combine(@"C:\Users\Mahsa\Desktop\" + Session.name)))
        {
            Controller.MarkController.AddMark(1, q1, 10, Session.id);
        }
        else
        {
            Controller.MarkController.AddMark(1, q1,0, Session.id);
        }

 and this is my class: 

public partial class PracticalQuestion
{
    public int Id { get; set; }
    public string Text { get; set; }
    public string Parameter { get; set; }
    public string Level { get; set; }
}