using System;

using System.Linq;

​

class School

{

    public string Name { get; set; }

    public Student[] Students { get; set; }

}

​

class Student 

{

    public string Name { get; set; }

}

public class Program

{

    public static void Main()

    {

        var schools = new [] 

        {

            new School(){ Name = "Big school", Students = new [] { new Student() { Name="Big Bob" }, new Student() { Name="Big Jack" } }},

            new School(){ Name = "Little school", Students = new [] { new Student() { Name="Little Jim" }, new Student() { Name="Little John" } }}

        };

        var allStudents = schools.SelectMany(s=> s.Students, (sk, st) => new { SchoolName = sk.Name, StudentName = st.Name } );

        foreach(var student in allStudents)

        {

            Console.WriteLine(student);

        }

    }

}

​