I've rewritten about 35 pdf pages into html. I no longer show the links to the pdf pages on my website. But Google indexed them originally as pdf's and still has them indexed. They are in a pdf folder at my web host, but that folder is not visible to the public. I have absolutely no need for the pdf's anymore. I would like to just toss them. That poses several questions: 1) Is it better to just keep them in that invisible pdf folder, since it gives me about 35 more indexed pages? 2) Or will the SEs consider that "duplicate content"? That is, having the same page in html and pdf format? 3) If I do delete that unneeded pdf folder, with its 35 pages, will that cause problems with the SEs that suddenly find 35 missing pages? I would appreciate any advice. Thanks.
Why not just redirect the pdf pages to the corresponding html pages? There are several ways to do this. If not, delete the pdf pages and add a 404 custom error page, preferably with full navigation and a search box, for visitors who try to access the pdf file (see http://www.psychlinks.ca/error.htm for an example).