Gillian is deciding whether to replace an old machine, and has assembled some information (refer to attachment File #1). She believes that the second-hand market value of either machine will decline over time in line with the depreciation schedule (eg. the old machine should sell for $3,000 today). If there are no taxes, and Gillian's required rate of return is 15% p.a.:
1) What is the optimal replacement cycle for the new machine?
2) Should the old machine be replaced now or next year?