Roby owes Macoy PhP 30M. He also owes PhP 30 M to Macoy and Siera Enterprises a company of which Macoy is the managing partner who is authorized to collect the credits of the partnership.

Roby pays Macoy PhP 50M informing him that the amount is the former's payment to the latter. In this regard, Macoy issued a receipt in the amount of PhP 50M.

Siera demanded that the payment should be applied equally to the loan of Roby to Macoy and the partnership. Is the demand of Siera reasonable?

Would your answer be the same if Macoy is not authorized to receive credits of the partnership?