using System;

using System.Linq;

using System.Collections.Generic;

​

public class Program

{

    public static void Main()

    {

        IList<Student> studentList = new List<Student>() { 

            new Student() { StudentID = 1, StudentName = "John", Age = 13 } ,

            new Student() { StudentID = 2, StudentName = "Moin",  Age = 21 },

            new Student() { StudentID = 3, StudentName = "Bill",  Age = 18 },

            new Student() { StudentID = 4, StudentName = "Ram" , Age = 20 },

            new Student() { StudentID = 5, StudentName = "Ron" , Age = 15 } 

        };

        var totalStudents = studentList.Count();

​

        Console.WriteLine("Total Students: {0}", totalStudents);

        var adultStudents = studentList.Count(s => s.Age >= 18);

        Console.WriteLine("Number of Adult Students: {0}", adultStudents );

​

    }

}

​

public class Student{

​

    public int StudentID { get; set; }

    public string StudentName { get; set; }

    public int Age { get; set; }

}