Three years ago Mahek borrowed R10 000 from Lettisha on condition that he should pay her back two years from now. He also owes Lettisha R6 000 payable five years from now. The applicable interest rate for both transactions is 13,75% per year, compounded half yearly. After considering his payback schedule, Mahek asks Lettisha if he can pay her R9 000 now and the rest in four years’ time. She agrees on condition that the new agreement will run from now and that an interest rate of 16,28% per year, compounded monthly, will be applicable from now. The amount that Mahek will have to pay Lettisha four years from now is