a) Siga-an granted a loan to Villanueva in the amount of P 540, 000.00. Such agreement was not reduced to writing. Siga-an demanded interest which was paid by Villanueva in cash and checks. The total amount Villanueva paid accumulated to P 1, 200, 000.00. Upon advice of her lawyer, Villanueva demanded for the return of the excess amount of P 660, 000.00 which was ignored by Siga-an. 1) Is the payment of interest valid? Explain. (3%) 2) Is solution indebiti applicable? Explain. (2%) b) Eulalia was engaged in the business of buying and selling large cattle. In order to secure the financial capital, she advanced for her employees (biyaheros). She required them to surrender TCT of their properties and to execute the corresponding Deeds of Sale in her favor. Domeng Bandong was not required to post any security but when Eulalia discovered that he incurred shortage in cattle procurement operation, he was required to execute a Deed of Sale over a parcel of land in favor of Eulalia. She sold the property to her grandneice Jocelyn who thereafter instituted an action for ejectment against the Spouses Bandong. To assert their right, Spouses Bandong filed an action for annulment of sale against Eulalia and Jocelyn alleging that there was no sale intended but only equitable mortgage for the purpose of securing the shortage incurred by Domeng in the amount of P 70, 000.00 while employed as "biyahero" by Eulalia. Was the Deed of Sale between Domeng and Eulalia a contract of sale or an equitable mortgage? Explain. (5%)