Solve clearly

In the use of unmanned aerial vehicles (UAVS) that will shape the future of UAV applications, an online shopping company wants to purchase a group of UAVS. As cargo drones are a proven technology for the logistics industry to obtain faster, more environmentally friendly service. The installation cost is 16000 TL and will reduce current expenses by 2400 TL per year for eight years. If the MARR is 10% per year; a) Find the minimum salvage value after eight years that makes the UAVs worth purchasing? b) Find the UAV's IRR if the salvage value is negligible? Use PW for linear interpolation