(A) No business of the Corporate Authorities shall be conducted without a quorum present. A quorum shall consist of at least 4 Aldermen or of the Mayor and at least 3 Aldermen.
(B) All ordinances for whatever purpose, and any resolution or motion to create any liability against the city or for the expenditure or appropriation of money, shall require the concurrence of a majority of all members of the Corporate Authorities then holding office. All ordinances, resolutions or motions to sell property, or to vacate streets and alleys shall require the concurrence of ¾ of the Aldermen then holding office.
(1992 Code, § 30.19)