PLEASE INCLUDE ALL CALCULATIONS(formulas etc), no excel please

3) A machine that a firm considers to buy in 2021 costs 4 000 000. Firm estimates the incremental cash flows expected that investment as follows

2022 1 500 000

2023 2 000 000

2024 2 000 000

2025 1 800 000

2026 1 400 000

The machine which has an estimated lifetime of 5 years may be sold at a value of 800 000 at the end of 2026 without leading to an additional tax burden. Given this

a) Calculate the exact payback period of that investment assuming that firm uses discounted payback period with a discount rate of 12%

b) Calculate the net PV of that investment using a discount rate of 12%

c) Write the relevant formula for IRR and calculate the IRR of that investment

d) Is that investment feasible according to a)Net PV b) According to Discounted Payback if firms target payback period is 3 years c) According to IRR if the risk premium of the investment is 5% and current riskless rate is 11%?