(2)No such appeal shall be entertained unless(a)it is accompanied by proof of payment, in such manner as may be prescribed, of the amount of tax admitted by the dealer to be due from him and ten per cent of the difference between such amount of tax including penalty and interest assessed; or(b)it is filed within forty five days of the date of passing of the orders as aforesaid or 30 days from the date on which the demand, if any, for tax or penalty is served or deemed to have been served on the dealer, whichever is later:Provided that the aforesaid authority may admit an appeal after the expiry of the said period, if on application by the dealer, it is satisfied that the dealer was prevented by sufficient cause from preferring the appeal within the aforesaid time.
