title: linq select within where clause
body: <p>i have a class and a collection with in it. </p>
  
  <pre><code>class A
  {
  B[] boxes;
  }
  
  class B
  {
  string boxNumber;
  }
  </code></pre>
  
  <p>Now, i need to create an object of type A that internally has B[] with only even box numbers.
  can anyone help me with the linq query?</p>