title: How do you multiply the first element in a list by a number (in a list of lists) in Python?
body: <p>I have a list of lists like this:</p>
  
  <pre><code>[[1,2,3],[4,5,6]]
  </code></pre>
  
  <p>I would like to multiply the first element of each of the inner lists by 10. So the expected output would be this:</p>
  
  <pre><code>[[10,2,3],[40,5,6]]
  </code></pre>
  
  <p>How could I do this?</p>