Upon the filing of such petition, the county clerk shall give at least ten (10) days' written notice to all the directors of the district of the filing of the petition and at any time after twenty (20) days from the service of such notice on the directors the matter may be heard by the court, either upon oral testimony or upon depositions or on documentary evidence and on all the records in the cause, or on all such evidence, and the court shall render decree according to the merits of the controversy.