please show calculations and if possible a timeline

2. A year ago an investor placed $10,000 in a savings account that was earning 5% a year with monthly compounding. After 3 months the bank dropped the rate to 4% a year and then three months later dropped the rate to 3% and finally after another 3 months dropped the rate to its current 2% a year. How much money did the investor earn in interest over the last year? 3. You decide you want to retire in 30 years. You decide to invest $5000 at the end of each year in a fund earning 8% a year over the next 30 years. How much money will you have at the end of the 30 years? Now assume each payment will be increased by 5% a year, e.g. the first payment will actually be $5250, the next payment $5,512.50, and so on. How much money will you have for retirement at the end of the 30 years