Answer:
Amortization for the year 2017 is $12,000
Step-by-step explanation:
Given:
Estimated Useful life = 30 years
Cost of Assets on January 1, 2007 = $540,000
Now,
The Amortization per year =

or
The Amortization per year =

or
The Amortization per year = $18,000
Thus,
Accumulated amortization on January 1, 2017
= Amortization per year 18000 × Number of years from 2007 to 2017
= $18,000 × 10
= $180,000
Therefore,
The Book Value of Asset on January 1, 2017 = $540,000 - $180,000
= $360,000
also,
The Revised useful life = 30 years
Therefore,
The Amortization per year =

or
The Amortization per year =

or
The Amortization per year = $12,000
Hence,
Amortization for the year 2017 is $12,000