Every employer of employes shall keep a true and accurate record of the hours worked by each employe and the wages paid to each, and shall furnish to the secretary or his or her duly authorized representative, upon demand, a sworn statement of the same. Such records shall be open to inspection by any duly authorized representative of the secretary at any reasonable time and shall be preserved for a period of three years. Every employer subject to this act shall keep a summary of this act and any regulations issued thereunder applicable to him or her, posted in a conspicuous place where employes normally pass and can read it. Employers shall, upon request, be furnished copies of such summaries without charge. Employers shall permit any duly authorized representative of the secretary to interrogate any employe in the place of employment and during work hours with respect to the wages paid to and the hours worked by such employe or other employes.