Initial outlay at the beginning of year $1=500,000.$ Desired rate of return$=18\%$Cash Flows into the Company:Year $1=100,000$Year $2=500,000$ and outflow $($expenditure$)$ of $200,000$Year $3=200,000$Year $4=300,000$

How do I find the NPV$,$ IRR, and the Payback?