which part of the bible has most pages the old or the new testtament
The number of pages will vary depending on the publication. But I believe the Old Testament has more books in it than the New Testament does, if that makes any difference.
The best you can do, I think, is to find a Bible in print -- or maybe several versions -- and check the pages.
The old T is much larger. Turn to the middle of any Bible, you will land near Psalms.
The old testament certainly has the most books which makes it much larger.