Please write out work!

Houston Metro is trying to decide which two time tracking device to install on the buses to reduce costs and travel time. Both devices cost S1000 and have useful lives of five years and no salvage value. Device will result in S300 savings annually. Device B will provide cost savings of $400 the first year, but will decline S50 annually, making the second-year savings S350, the third-year savings $300, and so forth. With interest at 7%, which time tracking device should Houston METRO purchase? (15-points)