You graduate and receive a $$$$10$ comma $000$ cheque from your grandparents. You decide to save it toward a down payment on a house. You invest it earning $10\%$ per$$ year, and you think you will need to have $$$$20$ comma $000$ saved for the down payment. How long will it be before the $$$$10$ comma $000$ has grown to $$$$20$ comma $000?$