Economics Homework Help

Can you help me understand this Finance question?

To live comfortably in retirement, you decide you will need to save $2 million by the time you are 65 (you are 30 years old today). You will start a new retirement savings account today and contribute the same amount of money on every birthday up to and including your 65th birthday. Using TVM principles, how much must you set aside each year to make sure that you hit your target goal if the interest rate is 5%? What flaws might exist in your calculations, and what variables could lead to different outcomes? What actions could you take ensure you reach your target goal?