Reordering of questions within the page works by drag and drop, pretty much the same as jrDocs.
Well, same same but different.
On a small screened laptop with a trackpad I find it hard to reorder tall sections when using jrDocs. As sections can be tall in ujQuiz (think of a 10 option multiple choice answer) the Quiz module uses a suitable variation.
To reorder questions click the reorder button at the top of the page. A sort of "table of contents" is revealed (to the profile owner only, and admin) and you drag and drop those "ToC" items to reorder the page. The page is updated instantly. Click the reorder button again and the "ToC" disappears.