Mohammad wants to buy a new car. He wants to save $6000 for down payment and finance the rest of the price.

a) If he can put aside $300 per month for the down payment in an account paying 6.2% compounded annually, how long will it take him to save $6000? Give your answer in years and months.

b) After saving $6000, Mohammad goes to a dealer to buy the car he wants. He ends up signing a contract the requires him paying $320 per month for the next four years at 3.99% compounded monthly. What is the cash price of the car he bought?