use excel to solve it, please explain

Exercise 2. Your proposed investment has forecast the following capital, sales and operating costs given below. Capital may be depreciated over 10 years on a straight line basis. Tax is assessed at 30 % of net profits after tax. The real discount factor is 5%. (a) Assuming a unit sale price of $AUD 1 per unit, determine: i. What is the tax payable in Year 3? Express as a single number. ii. What is the net after tax cash flow in Year 4? Express as a single number. iii. What is the NPV of this project? (b) What is the break-even price per unit? 0 1 2 3 4 to 25 Year Capital ($AUD) Annual sales (units sold) (60,000) 15,000 22,000 25,000 27,000