Paginations in Category Page Leads to Sample Pages

You should delete this part (as Pieter wrote):

$the_query = array(
    'paged' => $paged,
    'cat' => $cat,
    'posts_per_page' => 20,
);

$arrgs = new WP_Query( $the_query );

$temp_query = $wp_query;
$wp_query   = NULL;
$wp_query   = $arrgs;

I’m supposing that you want to show 20 posts per page, you could either configure that in Settings->Reading panel in the admin or do this:

query_posts($query_string . ‘&posts_per_page=20’);

And then the query as it is.