17. (1) The meetings of the Board shall be held at such times and at such places as may be prescribed by regulations: Provided that a meeting may also be otherwise convened by the Chairman when he so thinks fit and shall be convened if two or more Directors so request in writing addressed to the Chairman: Provided further that a meeting of the Board shall be held at least once in every three months. (2) To constitute a quorum at a meeting of the Board not less than three Directors shall be present. (3) At a meeting of the Board each Director shall have one vote, and in the event of equality of votes the Chairman shall have a second or casting vote. (4) No Director shall vote on any matter in which he is directly or indirectly interested. (5) If for any reason the Chairman is unable to be present at a meeting of the Board, a Director authorised in writing by the chairman shall preside at the meeting.