(b) (3) 14. 15. if such an address is not known and cannot by reasonable enquiry be ascertained, the enquiries shall be advertised in the Gazette. The prescribed time for reply to such enquiries shall be(a) to an enquiry duly sent by registered post, 14 calendar days after the second day following the posting of such enquiry; (b) to an enquiry duly advertised in the Gazette, 14 calendar days after the date of such advertisement. Determination of royalties (1) The royalty payable in terms of section 14 (1) (d) of the Act shall be 5 per cent retail selling price of the record as defined in regulation 12: Provided that, if the amount so calculated includes a fraction of a cent that fraction shall be reckoned as one half of a cent and if, but for his proviso the calculation would include a fraction of more than half a cent, that fraction shall be one cent. (2) In the case of a record comprising two or more musical works (with or without other material and either in their original form or in the form of adaptations) in which copyright subsists(a) the minimum royalty in the absence of an agreement as envisaged in regulation 11 (1) shall be one half of one cent in respect space of each of those works; and (b) if the owners of the copyright in the works are different persons, the royalty shall be apportioned among them in such manner as may be agreed upon by them or as may, in a default of agreement, be determined by arbitration I nspection Upon demand made by the owner of copyright or his duly authorised agent, the manufacturer shall permit the said person- 16. (1) to carry out a physical inspection of and check all stocks held by or on behalf of the manufacturer; (2) to examine the stock records of the manufacturer to check and determine(a) the number of records manufactured; (b) the number of records sold or delivered; and (c) the number of records on hand. Separate agreement It shall be competent for any persons who would otherwise be bound by the terms of the regulations in this Chapter to enter into a written agreement in