How the numbers work

[Mark Cherv]

Looking for some loan structuring advice.   

Lets say I have 50k cash of 70k needed for a real estate down payment.    I have friends and family that would be willing to make up the other 20k for a purely cash loan if they could make a return on their investment for little work.

Basically I would offer them some sort of return on their cash.   No equity involved.   I am unsure of how I should run numbers to see what works.   If I borrowed 20K for up to 2 year, how should l consider some reasonable returns for the investors?    

Any advice, book or article recommendations?

Thanks in advance