Suppose john has a mortgage. he currently owes $100,000, and is making monthly payments of $989 for a loan with 3.5% APR. he additionally has a...

Suppose john has a mortgage. he currently owes $100,000, and is making monthly

payments of $989 for a loan with 3.5% APR. he additionally has a retirement fund 

that he hopes will earn 4% APR.

1.Assume john pays exactly $890 for his house every month. 

How many years Until John pays off his house?