You are saving for a new house and you put $$10,000$ per year in an account paying $8\%.$ The first payment is made today. How much will you have at the end of $3$ years?

Suppose you want to borrow $$20,000$ for a new car. You can borrow at $8\%$ per year, compounded monthly per month$).$ If you take a $4$ year loan, what is your monthly payment?