title: How to sum a list of tuples
body: <p>Given the following list of tuples...</p>
  
  <pre><code>val list = List((1, 2), (1, 2), (1, 2))
  </code></pre>
  
  <p>... how do I sum all the values and obtain a single tuple like this?</p>
  
  <pre><code>(3, 6)
  </code></pre>