Person A starts working at 30 with no deposits. He retires at 65. His annual income is $60,000. He has to save some money to support his after-retirement life from 65 to 80. The constant interest rate is 5% per year. If(1) he chooses to maintain his after-retirement spending at the rate of 80% of his pre-retirement income, how much money should he deposit every year? if (2) he would like to maintain a constant spending before and after retirement, how much does he save every year