If a legal parent to whom notice must be given as aforesaid is within the State, a summons issuing under the seal of the court and containing a notification as to the time and place of hearing, shall be served by the sheriff or the sheriff’s deputy, any police officer, or any person authorized by court rule, upon such parent by the delivery to the parent of a certified copy thereof, and of the petition for adoption; or in case the parent cannot be found, by leaving copies of the summons and petition with some agent or person transacting the business of the parent, or by leaving such copies at the parent’s last known place of residence. When service is made pursuant to this section, the time appointed for the hearing of the petition shall be not less than ten days subsequent to the date of service as herein provided.