<prompt> Human: Okay so here is the down low. My father and I purchased a duplex. At the time he paid 55,000 and I paid 30,000. We are wanting to become partners and I need to pay 12,500 back to him.The duplex at the moment is renting for 1,150. When winter starts it will be at 1,200 a month.I own 35 of the duplex as of right now. So out of 1,150, I receive 402.50 a month. I want to just put that toward what I owe him.So next month my percentage will be higher as I keep rolling my money to pay him off. So this 35 will constantly change.Can someone please show me how much percentage and monthly payments I will be paying him until we are 5050?Please help me out. Thanks.  <response>: heres the excel spreadsheetkey-Dad and OP are respective amounts invested. Dper and OPper are respective percentages of ownership. Monthly income is rental price. Dmonin and OPmonin are respective monthly incomes. This spreadsheet assumes you roll the entire amount into ownership. You will reach parity in just over 2 years. 