ina owns a hostel in a large town. She bought a copy machine for $1,700, which has a life expectancy of 40,000 units. In the first year, Tina and her staff copied 800 units. In the second year, they copied 900 units, and in the third year they copied 1,400 units. Using the units of production method of depreciation, what is the value of the copy machine after year 3?