Sarah purchased a condo for $50,000 in 1987. Her down payment was $20,000. She financed the remaining amount as a $30,000, 30-year mortgage at 7%,...

Sarah purchased a condo for $50,000 in 1987. Her down payment was $20,000. She financed the remaining amount as a $30,000, 30-year mortgage at 7%, compounded monthly. Her monthly payments are $200. It is now 2007 (20 years later) and Sarah has sold the condo for $100,000, immediately after making her 240th payment on the unit. What is her effective annual internal rate of return on this investment?