Each of the matters of which an admission is requested shall be deemed admitted unless, within a period designated in the request, which shall not be less than fteen (15) calendar days after service thereof, or within such further time as the court may allow on motion, the party to whom the request is directed les and serves upon the party requesting the admission a sworn statement either denying specically the matters of which an admission is requested or setting forth in detail the reasons why he or she cannot truthfully either admit or deny those matters.