微观经济一道题

微观经济一道题
suppose you buy a home for $200000,using your own funds.The annual interest rate you could earn by investing your funds elsewhere is 5%.(Ignore any sales commissions or fees associated with buying or selling a home.)
a) if the price at which you could sell the home remains at $200000,what is your annual interest cost of home ownership?
b)suppose that,after a few years of owning,home prices rise dramatically,and you can sell it for $300000.If you continue to own,what is your annual interest cost now?
c) Suppose you can now sell it for $300000.But the interest rate you can earn by investing it is 7%.If you contine to own,what is your annual interest rate?
Thanx