The following machines were purchased during 2010:
Machine A for $6,000 on April 5
Machine B for $4,000 on August 24
Machine C for $5,000 on November 10
Assuming that each machine has an estimated useful life of six years and a 10 percent residual value, calculate total depreciation expense for 2010 (assume straight-line depreciation and round to the nearest month and the company reports on a calendar-year basis).