Where the proprietor liable to pay tax under section 3 or 4 is a firm or association of persons is dissolved or disrupted, as the case may be,
(a) The tax or interest or both and penalty payable under this Act by such firm or association of persons for the period upto the date of such dissolution or disruption 7 may be assessed, as if no dissolution or disruption had taken place and all the provisions of this Act shall apply accordingly, and
(b) Every person who was at the time of such dissolution or disruption a member or partner of firm or association of persons shall notwithstanding such dissolution or disruption, be liable severally and jointly for the payment of the tax including interest and penalty, if any, payable under this Act by such firm or association of persons, whether assessment is made prior to or after such dissolution or disruption.