I took $2.4 million and turned it into $36 million in 17 years = $2.117.647 return on my money and while a person did not need any brains, like I don't have, there are many people in California who did exactly the same as I did with NO THINKING, NO BRAINS, NO CONSTANT MANAGEMENT OF SHORT TERM RENTALS.I don't know how you do your math, but I'll kiss your buns if you can get me an average annual return in the stock market that is more than 5% with all the ups and downs, the 2000 to 2001 crisis and the February to March 2020 crisis, but I will be super generous to you and assume you are some sort of genius and you got me 8% by investing in the stock market.I will produce 2  charts.

That's very generous!

I'm not saying you should never offer a mentor something in return, but I have found that many people are generous with their time because they know that it will generally be reciprocated and often in quantities more than expected.Again, these relationships are built organically over time.  

And, let's also say your boss was so generous he/she gave you a $0.25 raise for all your hard 40/50 hrs you put in at work. 

If they are currently month-to-month, and assuming you are not in a rent-controlled area of CA, give them notice to vacate in 60 days, or 90 days if you are feeling generous.

say you get 20 miles to the gallon which is generous on average.. 

The $20-40k investment will more than likely(being generous) be recouped. 

We tried to be generous work out a payment plan for the deposit so they could pay $200 extra a month until the deposit was paid in full.

It looks like you have a have a good core plus asset with generous financing terms.

also a Big Shout out to BP for allowing Aheroshome.org to present our Charity, we are already seeing thousands flowing in and this should put us over the top to give our home away to a deserving first responder family  myself and our partners in this endeavor deeply appreciate and thank all for your most generous donations.