DEF Company is considering to accept one of the following two projects. The cash flow of

the two projects are as follows:

The company's cost of capital is $10$ percent. Calculate and answers to the followings:

$($a$)$ Payback period for both projects.

$($b$)$ Net present value for both projects.

$($c$)$ Profitability Index for project $x$ and $Y.$

$($d$)$ Which project would you choose and state your reasons.