Rules on Civil Procedure
Section 3. Answer to amended complaint. - When the plaintiff files an amended complaint as a matter of right, the defendant shall answer the same within fifteen (15) days after being served with a copy thereof.
Where its filing is not a matter of right, the defendant shall answer the amended complaint within ten (l0) days from notice of the order admitting the same. An answer earlier filed may serve as the answer to the amended complaint if no new answer is filed.
This Rule shall apply to the answer to an amended counterclaim, amended cross-claim, amended third (fourth, etc.) - party complaint, and amended complaint-in-intervention. (3a)