Solve using MFW and methods. A firm is considering which of two mechanical devices to install to reduce costs. Both devices have useful lives of 5 years and no salvage value. Device A costs $1,000 and can be expected to result in $300 savings annually. Device B costs $1,350 and will provide cost savings of $300 the first-year but will increase $50 annually, making the second year savings $350, the third-year savings $400, and so forth. With interest at 7%, which device should the firm purchase?