I need help with these questions, I have been struggling with the very last one for a few hours.

1. Suppose you win the lottery with a jackpot of $20 million. But thats $20 million if you wait 20 years to get your payout. What is the value you could get today if the interest rate is 6%?

2. If you save $250 each year for the next 20 years, how much money would you have if you earned 9%?

3.Figure out how much you need to save each year to reach one of your goals

2 year goal = 4% rate of return Goal: $2,500

How much do I need to save a year with a 4% interest rate to reach my goal of $2500 in 2 years? What formula do I use to solve this and how?