using System;
using System.Linq;
using System.Collections.Generic;

public class Test
{
	public static void Main()
	{
		List<Student> myList = new List<Student>();
        myList.Add(new Student("John", 10));
        myList.Add(new Student("Tom", 20));
        foreach ( var tom in myList.Where(w => w.Name == "Tom")) {
            tom.Marks = 35;
        }
        foreach ( var s in myList) {
        	Console.WriteLine("Name='{0}, Marks={1}", s.Name, s.Marks);
        }
	}
}

class Student {
    private string name;
    private int marks;
    public string Name { get; set;}
    public int Marks { get; set; }
    public Student(string name, int marks) {
        Name = name;
        Marks = marks;
    }
}