Because of a chronic water shortage in California, new athletic fields must use artificial turf or xeriscape landscaping. If the value of the water saved each six-months is $3,500, how much can a private developer afford to spend now on artificial turf provided he must recover his investment in 5 years. Use an interest rate of 17% per year, compounded continuously?

I've seen this question asked a few times on chegg already, but none of the answers were correct and the equations used on them didn't get me the right answer either.