title: Decision Tree - Can the Entropy of a Node be Zero?
body: <p>The formula for information gain is give by,</p>
  
  <pre><code>Information Gain = entropy(parent) – [average entropy(children)]
  </code></pre>
  
  <p>Can the entropy be zero, which means in some case: </p>
  
  <pre><code>entropy(parent) == [average entropy(children)]
  </code></pre>