4- A residential rental holding was purchased on January 1 of 2000, then was sold on January 1 of 2024, if MACRS depreciation system is applied, then in order to calculate the book value of the property on January 1 of 2009, 8.5 years of the depreciation should be considered. (T/F) 5- Increasing the magnitude of the initial investment result to decrease the optimum replacement interval. (T/F) 6- In replacement analysis, the cash flow approach meaningful only if the defender and challenger have the same service life. (T/F)