Please help find the PERCENTAGES for 3&4.

You Borrow money on a self liquidating installemnt loan (equal payments at the end of each year, each payment is part principal part interest) Use the installment method - not straight line What is the annual payment? What is the total interest payments? After half the payments have been made, what percentage of the total interest has been paid (round to the nearest percentage point)? After half the payments have been made, what percentage of the total principal has been paid (round to the nearest percentage point)