No excel, I need to be able to work it out on a test. Thank you

Bigbox, Inc. is considering two, mutually exclusive projects. Project A is a three-year project that has an initial after- tax cost of $90,000 and afer-tax cash inflows of $45,000 in year 1, $43,200 in year 2, and $28,800 in year 3. Project B has an after tax cost of $49,500 and future after-tax cash inflows of $47,370 in year 1 and $15,840 in year 2. If Bigbox uses the net present value method and has a discount rate of 3%, which project should they choose? Choose project B Choose project A Choose either A or B but not both Choose both projects You cannot determine which project is better since they have unequal lives