Ato Bekele is thinking of buying a G+2 building 5 years form now on a mortgage basis. The building will be used for office purpose for his new business that costs Br. 500, 000. The required down payment is Br. 100, 000, with monthly mortgage payment for 30 years at a rate of 12% compounded monthly. To cover the down payment Bekele has established a sinking fundaccount in Dashen Bank, which pays 10% interest compounded quarterly.