a company is considering two mutually exclusive projects a and b, project a costs rs. 30000 and project b rs. 36000. the npv probability distribution for each project is as given below:
project a project b

npv estimate probability npv estimate probability
rs.3000 0.1 rs.3000 0.2
6000 0.4 6000 0.3
12000 0.4 12000 0.3
15000 0.1 15000 0.2

how to compute :
1.) the expected net present value of projects a and b.
2.) the risk attached to each project i.e standard daviation of each probability distribution.
3.) the profitability index of each project.

which project will be more risky or why ?