problem: You are 40 years old and plan to retire in exactly twenty (20) years. Starting 21 years from now you will need to withdraw $5,000/year from your retirement fund to supplement your social security payment. If you expect to live to age eighty-five (85) how much should you place in the retirement fund each year for the next twenty (20) years to reach your retirement goal, suppose you can earn 12 percent per year on your retirement fund investment? Show your formulas & input