title: What is the maximum number of comparisons required to find a key in a binary tree having 191 nodes and whose height is equal to nine?
body: <p>I know that for a completely filled binary tree, the height of that tree is equal to <code>floor(log2(N))</code>, and that the maximum number of comparisons to find a given key is simply <code>h+1</code>, or <code>floor(log2(N)) + 1</code>.</p>
  
  <p>This question appears in the review for our final, and I cannot recall how to find the answer. The possible answers given are <code>7, 8, 9, 10</code>. I am fairly certain the answer is either <code>9</code> or <code>10</code>, but I don't know, because I'm not sure if I should be calculating the answer based upon the number <code>512</code> (<code>2^9</code>), or <code>191</code>.</p>
  
  <p>Help appreciated!</p>