I have the answers for this question, but I need assistance understanding how to calculate the NPV in both excel and in writting preferably please.

You are a consultant to a large manufacturing corporation considering a project with the following net after-tax cash flows in millions:

Years frm Now	After-Tax Cash Flows
0	20
19	10
10	20

The project's beta is 1.7. Assuming rf = 9% and E(rM) = 19%.

a. What is the net present value of the project? NPV is 15.64

because CAPM is .09 +(1.7*(.19-.09)) = .26. Please, how do I use this to also get NPV from here. Im not understanding how the answer got to 15.64

b. What is the highest possible beta estimate for the project before its NPV becomes negative? Highest poss. beta value is 4.055

to get this we calculate IRR which is 49.55% and plug in for CAPM 49.55%=9% + B(19%-9%) = 4.06