Derek decides to buy a new car. The dealership offers him a choice of paying $581.00 per month for 5 years (with the first payment due next month) or paying some $28,936.00 today. He can borrow money from his bank to buy the car. What interest rate makes him indifferent between the two options?

Derek wants to withdraw $14,183.00 from his account 8.00 years from today and $12,022.00 from his account 13.00 years from today. He currently has $3,381.00 in the account. How much must he deposit each year for the next 13.0 years? Assume a 5.56% interest rate. His account must equal zero by year 13.0 but may be negative prior to that.