It is a mathematical fact that if you are buying a rental property in any city where the monthly mortgage payment exceeds monthly rental income, or where mortgage payments along with monthly expenses exceed monthly rent, if any of those scenario applies, a down payment would be only other material method to avoid a negative cash flow situation.You let the investor worry about his gamble on the market going up.. thats not your problem.

Mathematics or business classes would be good

The one great standout way, the royal road, simply does not exist.The question, as I'm reading it, is how to go from taking home $120,000 a year FREE AND CLEAR (FCF= Free Cash Flow), to taking home $1.2M FCF.Imagining that it's going to come from ONE WAY is a mathematical wet dream.

Mathematically, that's the highest return possible because what could be a higher return than something for nothing?

Now as to whether you should sell or not this year, it is a purely mathematical one.

So far, these are the questions I have for myself at the moment:What factors must you include in your mathematical system?

I only pointed out the mathematical fact that the .5% rent ratio means the market has determined that the rent in that market is more desirable.  

I propose this challenge: if anyone can mathematically prove how the time spent writing off some mileage business expense or the frappucinos we buy every day into Mint, does NOT make you lose money (in the time-value of money way I just explained above), I will paypal you $500.00.

Amortization of the loanFrom a strictly mathematical point of view it is better to invest as early as possible to take advantage of all of this while maintaining your resolve to eliminate your debts quickly.  

It's not mathematically possible over time.