Recently, our college has replaced the computer system in each classroom - control panel, software, and projector. The total amount was $240,000 (this is an arbitrary amount). The entire system will be used 3 years. Due to the nature of high-tech equipment, they will have zero ($-0-) value at the end of the third year. What is the (net) book value of the computer system at the end of the 2nd year?