Are you really pinging? Why not just try them in your browser? Can you access the Servlet and JSP examples that come packaged with Tomcat?
One common problem is that people make their html file using Notepad and then do not change the "Save as Type" (.txt text file is the default), resulting in an actual file name of: somefile.html.txt even though windows hides the final extension.
Have you tried using an image or other kind of file?