A local company took a loan to purchase new delivery vehicles. They planned to
repay the loan in two instalments. The company made the first repayment of R15,000
after four years and the second repayment of R10,000 three years after that. The
interest rate for the first four years was 8%, compounded quarterly. However, due to
the increase in interest rates, the rate for the remaining three years was 10%
compounded annually. Calculate the original loan amount.