Equipment that cost $66,000 and has accumulated depreciation of $30,000 is exchanged for equipment with a fair value of $48,000 and $12,000 cash is received. The exchange lacked commercial substance. The new equipment should be recorded at:

a. $48,000.

b. $36,000.

c. $30,000.

*d. $28,800.

Answer is d but please show work and formulas are applied..

Recognized gain?