Where the business in respect of which any tax, interest or penalty is payable under this Act is carried on by any guardian, trustee or agent of a minor or other incapacitated person on behalf of and for the benefit of such minor or other incapacitated person, the tax, interest or penalty shall be levied upon and recoverable from such guardian, trustee or agent in like manner and to the same extent as it would be determined and recoverable from any such minor or other incapacitated person, as if he were a major or capacitated person and as if he were conducting the business himself, and all the provisions of this Act or the rules made thereunder shall apply accordingly.