here in section "b" we can get the deprecation ?

50,000 /40 =12,500

we can add the deprecation or not ? 50,000/4=12,500

b) A project requires an initial cash outflow of RO 50,000. The cash inflows before tax for 4 years are RO30,000, RO20,000, RO10,000, RO40,000. Corporation tax, at a rate of 5% of taxable income, is payable. The firm's cost of capital is 12%. Calculate, Payback period, Discounted Pay-back period and NPV. Compare between the first two results as a manager which one you will select and why? (PV@12% 11.8929, Y2.7972, 73.7118)