Find the values of following annuities on December 31, 2020 using 5% interest. a) Payments of $2,000 made on the first day of January , April, July ,and October starting in 2015. b) Payments at the rate of $15,000 per year made continuously from June 1, 2013 to May 31, 2019. c) Payments of $35,000 per year starting on January 1, 2024 and continuing for ever