Can you please explain this finance problem step by step as it will really help me out. thanks

BCL Company is evaluating two mutually exclusive projects: The Pinto grinder involves an outlay of $100,000, annual after-tax operating cash flows of $45,000, an after-tax salvage value of $25,000, and a four-year life. The Bolten grinder has an outlay of $50,000, annual after-tax operating cash flows of $40,000, an after-tax salvage value of $20,000, and a two-year life. The required rate of return is 10 percent. Draw the cash flow diagrams and find out the net present value (NPV) for both the projects. Also, given the unequal lives of the two alternatives, please find out which one should prefer