two partners in a business. one partner mortgaged business property to his co-partner for $15,000.00 at 12% a year interest. no payments were ever made for 17 years. how much is owed?

Answer 1

Where was the co-partner these 17 years?

Anyway, assuming the interest is compounded yearly, the money owed is:
A=$15000*1.12^17
=$102,990.61

Good luck, and don't forget to check the market value of the mortgaged property.