Jane has been saving $500 in her retirement account each month for the last 20 years and plans to continue contributing $500 each month for the next 20 years. Her account has been earning an 8% annual interest rate (APR) and she expects to earn the same rate for the next 20 years. Her twin brother, Hal, has not saved anything for the last 20 years. Due to sibling rivalry, he wants to have as much as Jane is expected to have at the end of 20 years. a) If Hal expects to earn the same annual interest rate as Jane, how much must Hal save each month to achieve his goal? b) If Hal decided that the most he can afford to save is $1,000 a month then what APR would he need to earn to match Jane's savings?