Engineering Economy 7th Edition by Leland Blank ,Anthony Tarquin

تمرين 19

The table below shows present worth calculations of the costs associated with using a presently owned machine (defender) and a possible replacement (challenger) for different numbers of years. Determine when the defender should be replaced using an interest rate of 10% per year and a 5-year study period. Show solutions
a) by hand and b) by spreadsheet.