3.4

        private static void CoursesOnAGivenDate(StudentSystemDBContext context)
        {
            var date = context.Courses.Select(s => s.StartDate).OrderBy(x => x).Skip(2).FirstOrDefault();
            Console.WriteLine("Given date:" + date.ToString("dd/MM/yyyy"));
            var courses = context.Courses.Where(x => x.StartDate < date && x.EndDate > date).ToList();

            foreach (var course in courses.OrderByDescending(x => x.Students.Count).ThenByDescending(d => d.EndDate - d.StartDate))
            {
                Console.WriteLine($"Course name: {course.Name} Start: {course.StartDate.ToString("dd/MM/yyyy")} End: {course.EndDate.ToString("dd/MM/yyyy")} Duration {(course.EndDate - course.StartDate).Days} days Enrolled: {course.Students.Count}");
            }
        }