And most of us are playing the long game here...time is the ultimate multiplier and hedge.https://irma.nps.gov/STATS/

Ok, so let's examine a potential deal:Purchase: 175kRehab: 55kARV: 350kSo right away, I wanna take the ARV and multiply it by 72.5%.

You multiply miles by mileage amount and that gives you a tax deduction.

Take that time and multiply it by the attorney's hourly rate, then discount it by their "efficiency." 

Now multiply this error by the entire house, by 4 units, by 8 units.

Still, if you look around at the colleges and universities the cost per credit hour multiplied by the hours for which one might enroll for a single year of college can easily exceed even the sum that I paid.

Looking at Cap Rates, Gross Rental Multiplier among other tools. 

So you multiply by 75% instead of 50%, and put taxes on the back end of the equation (taxes aren't explicitly in the 50% rule, so we need to add them somewhere).

From your example, I divided 7%(.07) by 12, and then multiplied that by $25,000 to get the monthly payments of $145.83.

Multiply the principal by the interest rate then divide by 12. $100,000 loan x 11% interest = $11,000 / 12 = $916.67 monthly payment