Carlton Company sells office equipment on September 30, 2010, for $21,000 cash. The office equipment originally cost $72,000 and as of January 1, 2010, had accumulated depreciation of $42,000. Depreciation for the first 9 months of 2010 is $6,000. Prepare the journal entries to (a) update depreciation to September 30, 2010 and (b) record the sale of the equipment.