title: sequential vs. binary search
body: <p>Consider a file on disk containing 100 records.</p>
  
  <p>For both searches, what is</p>
  
  <ol>
  <li>the average number of comparisons needed to find a record in a file.</li>
  <li>number of comparisons if the record is not in the file</li>
  <li>the average number of comparisons if the record has a 68% chance of being in the file</li>
  <li>the number of disk accesses in the previous 3 questions if the file has 25 records per block</li>
  </ol>