(a) Any party may serve, by mail or delivery by hand, upon any other party written interrogatories relating to any matter, not privileged, that is relevant to the subject matter involved in the pending action, whether it relates to the claim or defense of the party seeking discovery or to the claim or defense of any other party, including the existence, description, nature, custody, condition and location of any books, documents, electronically stored information, or other tangible things and the identity and location of persons having knowledge of any discoverable matter.
(b) A party may propound more than one set of interrogatories to an adverse party, but the total number of interrogatories shall not exceed 25, unless the court otherwise orders for good cause shown after the p