In all such special municipal separate school districts which may be so organized, reorganized or reconstituted to embrace the entire county in which the majority of the inhabitants of the county reside outside the corporate limits of the municipality, the name of any qualified elector who is a candidate for the board of trustees of such special municipal separate school district, whether such person be a candidate for an unexpired term or for a full term, shall be placed on the ballot used in the elections, provided that the candidate files with the county election commissioners, not more than ninety (90) days and not less than sixty (60) days prior to the date of such general election, a petition of nomination signed by not less than fifty (50) qualified electors of the county. Where there are less than one hundred (100) qualified electors in said area represented by the trustee, it shall only be required that said petition of nomination be signed by at least twenty percent (20%) of the qualified electors in said area. However, in any such special municipal separate school district which embraces the entire county and which borders the Mississippi River and in which Interstate Highway 20 and United States Highway 61 intersect and having a population in excess of forty-seven thousand (47,000) according to the 1990 federal decennial census, the candidate shall be required to file a petition of nomination with the county election commissioners not less than sixty (60) days prior to the date of such general election, in addition to the other requirements prescribed herein.

The candidate in each election who receives the majority of votes cast in the election shall be declared to have been elected. If no candidate receives a majority of the votes cast at the election, a runoff shall be held between the two (2) candidates receiving the highest number of votes in the first election. The runoff election, in the event that such is necessary, shall be held three (3) weeks after the first election.