Manufacturing Incorporated had the following disclosure in its significant accounting policy note: The amortization of PP& E is calculated on a straight- line basis over the following useful lives:
Buildings 5 to 75 years
Equipment 2 to 15 years
Other 3 to 20 years

Required:
1. Why is there a range for useful lives?
2. How could a building have a useful life of only five years and equipment for two years?