Calculate the total amount of interest for a loan of 1000 euros for a period of 10 years, for each of the three payment cases: 1) To pay the full amount of the loan together with the interest at the end of 10 years. 2) The interest to be paid every year and the loan capital once out at the end of 10 years. 3) The loan to be repaid with annual payments at the end of each year. Consider annual ERI = 9%.