title: LINQ group by and SUM
body: <blockquote>
    <p><strong>Possible Duplicate:</strong><br>
    <a href="https://stackoverflow.com/questions/2432281/get-sum-of-two-columns-in-one-linq-query">Get sum of two columns in one LINQ query</a>  </p>
  </blockquote>
  
  
  
  <p>I need to know how to write an LINQ Query that will give me the same results as this SQL Query 
  :</p>
  
  <pre><code>select sum(col1) as [col1] , sum(col2) as [col2] , sum(col1)/sum(col2) as [col3], col4 as [col4] 
  from some_table 
  group by col4
  </code></pre>