Given the cash flows for the following projects:

Year	Project Z Cash Flow (₹)	Project AA Cash Flow (₹)	Project AB Cash Flow (₹)
0	-7,000	-8,000	-6,000
1	2,000	2,500	1,500
2	2,500	3,000	2,000
3	3,000	3,500	2,500
4	3,500	4,000	3,000

Requirements:

1. Calculate the payback period for each project.
2. Select the project based on a payback period of 2 years.
3. Compute the discounted payback period at a discount rate of 13%.
4. Determine the NPV at a discount rate of 13%.
5. Calculate the profitability index for each project.