Solution 

<!DOCTYPE html>
<html>
  <head>
     <title>kitties</title>
  </head>
  <body>
    <div>
      <?php
      for ($i = 1; $i <= 5; $i++) {
	print("<img src=\"http://www.cs.washington.edu/education/courses/cse154/13sp/sections/kitties/kittie{$i}.jpeg\" />");
      }
      ?>
    </div>
  </body>
</html>