Suppose shaan invested just $13.600 of his own money and had a $122.400 mortgage with an interest rate of 8.5 percent. After three years, he sold the property for $163,200. a. What is his gross profit? b. What is his net profit or loss? Note: Negative amount should be indicated by a minus sign. c. What is the rate of return on investinent? Note: Negative amount should be indicated by a minus sign. Enter your answer as a percent rounded to 1 decimal place