Which project would you consider most liquid

Using Excel

1.)
Three separate projects each have an initial cash outlay of $10,000.
The cash flow for Peter’s Project is $4,000 per year for 3 years. The
cash flow for Paul’s project is $2,000 in years 1 and 3, and $8,000 in
year 2. Mary’s Project has a cash flow of $10,000 in year 1, followed by
$1,000 each year for years 2 and 3.

a) Use the payback method to calculate how many years it will take for each project to recoup the initial investment.