Candidates for nomination for each of the elective offices provided for in this Charter shall file petitions for nomination with the Mahoning County Board of Elections not less than ninety (90) days before the day of the primary election. Each candidate shall file a separate petition; group petitions shall not be used. 
   Such petitions for nomination shall state the name and place of residence of the person whose name is presented for a place upon the ballot and that he is a candidate for the designated offce of the City of Campbell, Ohio, and shall be signed by the candidate. Such petition may be in separate parts and all parts shall be assembled and filed with the election authorities as one instrument. 
   Such petition for nomination, if for the offices of Mayor or Council President, shall be signed by not less than one hundred (100) and not more than two hundred (200) qualified electors of the city. The petitions for nomination for the offices of Ward Councilmen shall require not less than twenty-five (25) and not more than fifty (50) signatures of the qualified electors of the ward for which the office of Ward Councilman is being petitioned.