You may have created a project and wish to change the number of pages in it. Some look for a simple box, just to enter a new number into it and it changes the project to that number of pages.
Sorry, we do not have a simple option like this. Each page in a project is in itself a stand alone page, all the pages don't get joined together until the PDF is created. So we did create work arounds for this.
You can click Add Page on the left side, the page view, or right click and delete a page on the left side where the page view is.
Please see these 2 FAQ's on adding and deleting pages.
[STUDIO] Can You Add a Page or Multiple Pages at Once in a Project?
[STUDIO] How Do You Delete a Page or Multiple Pages at Once?
When doing research which you should do no matter the book you make, besides seeing what books and how many are in the niche, you should be seeing how many pages the books selling have, and price as well. At least knowing the pages you will have, will save some time.