Answer:
Cash                  52.000 Â
Accumulated depreciation  30.000 Â
  Gain on asset disposal         2.000
  Ofiice equipment             80.000
Explanation:
        2012 2013 2014 2015
Cost    75000 67.500 60.000 52.500
Dep-Acu  7.500 7.500 7.500 7.500
Book Value 67.500 60.000 52.500 45.000