I know mathematically it seems to make sense, but the banks require a down payment, which is a percentage of the purchase price, not a percentage of the value of the house. 

You need to know the cultures involved, the income levels involved, who would be likely to rent your unit and what they would do with it and how likely they are to stay and not cause problems.There is no mathematical formula that figures that into the equation, so to speak. 

There may be some mathematical formula out there that proves a certain font/ font size/ color/ sign color will allow the client to see better.

I just don't DO them because it's a mathematically bad idea.

Lol mathematically much of his advice sucks.

Some landlords use a mathematical equation, called RUBS, to bill based on the size of the unit or other factors, this is just as inaccurate and down right illegal in a lot of places. 

Mathematically the federal government must run a deficit at least equivalent to the trade deficit in order for the private sector to achieve sustainable growth.

Mathematically, the Seller will just add the 3% commission back to the sales price.

I can mathematically prove to you cold calling is bad!

It depends on the person and what return they can get on there money you can mathematically determine which route is best by doing a discounted cash flow analysis to compare the three strategies.