Each page of results returned for a query uses a single transaction and will count toward your transaction limit.
A transaction is one request that returns one page of results. Retrieving multiple pages will result in multiple transactions executed.
I am unable to find any place where it tells how pages are calculated. Is it amount of results returned (what if I ask for top 10) or it depends on sources requested (web+image+video+news+spell)? Anyone working on it or knowledge on it, please provide some
It seems Bing won't return the exact the number of total result. Using "Next" button after numeric button now. You can open the Bing page and try to do a search to see the paging template. Use this to get paging: /feed/link[@rel=’next’].
For the Transaction issue, refer this thread. It explains: