Suppose that on 3/1/15, Mask, Inc. purchases equipment worth $6,000, paying cash. Assume the equipment will be useful the next 5 years and has $0 salvage value and that Mask, Inc. allocates the cost of this equipment equally over its useful life. Assume the end of the annual accounting period occurs each year on 12/31. What is the Net Book Value of this equipment, after making all adjusting entries, on 12/31/15