- manager of Malan Pty Ltd wants to buy a new machine to replace the one currently being used. The new chine will cost $100 000 with no disposal value at the end of a five-year useful life. The manager estimates that t chine will reduce annual operating costs by $30.000. Depreciation allowed for tax purpose will be $20 000 per r for five years. The tax rate for each year is expected to be 20 per cent and the company's after-tax required rat return is 12 per cent. What is the after-tax payback period of the machine? act one a. 4.17 years 6.3.33 years c. 3.57 years d. 4.55 years