The XNPV function can calculate NPV for any $($possibly irregular$)$ series of cash flows. Look this function up in Excel's online help. Then use it to develop a spreadsheet model that finds the NPV of the following series: a payment of $$25,000$ today $($assumed to be June $15,2017),$ and cash inflows of $$10,000$ on March $1,2018$; $$15,000$ on September $15,2018$;$$8000$ on January $20,2019$; $$20,000$ on April $1,2019$ ; and $$10,000$ on May $15,2019.$ Discount these back to "today" using a discount rate of $12\%.$