Every employer shall keep true and accurate records of hours worked by each employee, the wages paid, and such other information as the commissioner deems material and necessary, and shall, on demand, furnish to the commissioner or his duly authorized representative a sworn statement of the same. Every employer shall keep such records open to inspection by the commissioner or his duly authorized representative at any reasonable time. Every employer of an employee shall keep a digest or summary of this article and regulations, which shall be prepared by the commissioner, posted in a conspicuous place in his establishment and shall also keep posted such additional copies of said digest or summary as the commissioner prescribes. Employers shall, on request, be furnished with copies of this article and regulations, and of digests or summaries thereof, without charge. Employers shall permit the commissioner or his duly authorized representative to question any individual employed by such employer in the place of employment and during working hours in respect to the wages paid and the hours worked when records of hours worked are required under this article.