title: how to select list of another list in EF
body: <p>I have this class</p>
  
  <pre><code>public class Student
  {
      public string Name { get; set; }
      public int Grade { get; set; }
  }
  </code></pre>
  
  <p>and I fill my list by this method,</p>
  
  <pre><code>private static void FillLists()
  {
      List&lt;Student&gt; lststudent = new List&lt;Student&gt;();
      lststudent.Add(new Student { Name = "Arash", Grade = 12 });
      lststudent.Add(new Student { Name = "Kamran", Grade = 13 });
      lststudent.Add(new Student { Name = "koroush", Grade = 16 });
  
      List&lt;Student&gt; lststudent2 = new List&lt;Student&gt;();
      lststudent2.Add(new Student { Name = "Arman", Grade = 18 });
      lststudent2.Add(new Student { Name = "Aria", Grade = 10 });
      lststudent2.Add(new Student { Name = "Daryoush", Grade = 20 });
  
      List&lt;List&lt;Student&gt;&gt; students = new List&lt;List&lt;Student&gt;&gt;();
      students.Add(lststudent);
      students.Add(lststudent2);
  }
  </code></pre>
  
  <p>my question is How can I get a list of the <code>grade &gt; 15</code> students?</p>