Joe rossell purchased a rental house for $80000. after a year, joe spent $10000 to improve the property, primarily the kitchen and bathrooms.

at the end of the second year, he spent another $5000 on capital improvements and rented the house to a tenant for $9000 for the entire second year. he rented the house the following 2 years and recieved $9500 at the end of the third year and $10000 at the end of the forth year.

He did not spend any additional amounts on improvements in years 3 or 4. joe became weary of being a landlord and sold the house at the end of year 4 for $120000. What was Joes internal rate of return on this investment?