A company is considering an investment in new equipment costing ₹700 lakhs. The equipment has a useful life of 7 years and no salvage value. The expected revenues and expenses from the investment are as follows:

Year	Revenue (₹ in lakhs)	Expenses (₹ in lakhs)
1	300	100
2	320	110
3	340	120
4	360	130
5	380	140
6	400	150
7	420	160

The discount rate is 15%.

Required:

1. Calculate the NPV of the investment.
2. Determine the IRR of the investment.
3. Compute the Profitability Index (PI).
4. Evaluate the investment's sensitivity to a 2% increase in expenses.