If a majority of the votes cast in both the largest city and in the county as a whole (including the largest city and the other cities) is for consolidation and charter adoption, reorganization shall be deemed approved and the charter adopted, and the clerk of the legislative body of the county shall forthwith prepare under seal, and deliver to the clerk of the legislative body of each of the cities and to the county clerk, a copy in duplicate of the record of the canvass, with a statement of the proposition or propositions submitted, at the election.