Answer:
b.$60,000.
Explanation:
First we have to find the depreciation rate which is shown below:
= One ÷ useful life
= 1 ÷ 3
= 33.33%
Now the rate is double So, 66.66%
In year 1, the original cost is $900,000, so the depreciation is $600,000 after applying the 66.66% depreciation rate
And, in year 2, the $200,000 ($900,000 - $600,000) × 66.66%
And, in year 3 it is ($100,000 - $40,000) = $60,000
The $100,000 is come from
= $900,000 - $600,000 - $200,000
= $100,000