title: How to SUM parts of a column which have same text value in different column in the same row
body: <p>I have a column with names and a column with numbers: </p>
  
  <pre><code>FirstName    Name    Number
  John         Smith     17
  John         Smith     26
  Peter        Smith     116
  Peter        Smith     25
  Franck       Black     17
  Luke        Peterson   17
  Luke        Peterson   37
  </code></pre>
  
  <p>Names with same <code>FirstName</code> and <code>Name</code> represent the same person. I need to sum the numbers associated with them. I prefer not to use VBA.</p>