Piyush initially took a loan from Vivek at a simple interest rate of 8% per annum, and after a duration of two years, he repaid the borrowed amount. Subsequently, he secured another loan amounting to two-thirds of the initial sum from Rajan, also at a simple interest rate, but at 12% per annum for another period of two years. The aggregate sum borrowed by Piyush across these transactions totaled Rs. 25,000. Calculate the total amount Piyush repaid to both Vivek and Rajan.