X16. Two wealthy grandparents want to set up a trust fund for their newly born granddaughter, and all of their granddaughter's descendants (i.e. their great-grandchildren, great-great-grandchildren, etc.). They want their granddaughter to receive $100,000 a year beginning on her 20 th birthday (i.e. 20 years from now), and continuing forever (again, their granddaughter will be able to leave this source of income to her descendants). If they want to set aside the funds today to create this fund for their granddaughter, and assuming they can earn 9% returns (interest) on their savings, how much do they need to set aside today