Answer:
$22000 and $50000.
Explanation:
Given: Purchased value of equipment- $72000.
Residual value- $6000
Estimated useful life of equipment- $ 5 years.
Now, finding value of depreciation for 2011 using the sum of the years digits method.
Depreciation cost= 
⇒ Depreciation cost= 
∴ Depreciation cost= $66000.
Depreciation fraction for 1st year= 
Depreciation expense for 1st year= 
∴ Depreciation for 2011 is $22000.
Next, lets find out the book value at the end of first year.
Book value= 
Book value= 
∴ Book value at December 2011 is $50000.