This is not a problem.
The issue with duplicate content is that you lose control over the copy that appears in the search results. Google will only show one page from your site if it thinks they are the same content. If Google sees each of your pages as unique then you can manipulate the positioning of the pages in the results.
So duplicate content is not an issue on the same page. You do however need to be wary of keyword stuffing i.e. putting in the keywords an unnatural amount of times.
