Any contestee upon whom a notice of contest as described in section
382 of this title shall be served, shall, within thirty days after the service thereof, serve upon contestant a written answer to such notice, admitting or denying the averments upon which contestant relies. If contestee is without knowledge or information sufficient to form a belief as to the truth of an averment, he shall so state and this shall have the effect of a denial. Such answer shall set forth affirmatively any other defenses, in law or fact, on which contestee relies. Contestee shall sign and verify such answer by oath or affirmation.