You receive a $$$$9000$ check from your grandparents for graduation. You decide to save it toward a down payment on a house. You invest it earning $10\%$ per year and you think you will need to have $$$$18000$ saved for the down payment. How long will it be before the $$$$9000$ has grown to $$$$18000?$ To double the money you received from your$$ grandparents, it will take $($enter your response here$)$ years.$$