a$)$ An airline currently tickets an average of $6,000$ passengers daily. This task involves $50$ employees at an average annual salary of $$12,000$ each. A computer firm proposes a ticketing system which can do the job $($including system maintenance$)$ with only $30$ employees. The system$$s purchase can be financed by borrowing at $15$ percent per year. At what price does the system become attractive to the airline? b$)$ Now, suppose that it is expected that, due to technical developments, the price of the above system will decline at an annual rate of about $5\%$ for the foreseeable future. At what price does the system now become attractive?