A loan of $10,000$ is being repaid with 20 non-level annual payments. The interest rate on the loan is an annual effective rate of$6$% . The loan was originated 4 years ago. Payments of $500$ at the end of the first year, $750$ at the end of the second year, $1000$ at the end of the third year, $1250$ at the end of the forth year have been paid.
Calculate the outstanding balance immediately after the forth payment.
I tried through
Present value of all payments = Amount of Loan
Getting some problems here. This equation does not fit in.