time value of money / using excel sheet

An investor sets aside $10,000 when they are 18 years old. How much will the investor have accumulated at the end of 50 years if he/she can earn an average return of 8%? How much will be accumulated in the account if the investor earns 10% instead of 8%?

An investor has determined that they need to accumulate $1,500,000 for retirement in 35 years. How much should this investor set aside each year in order to meet this goal if they expect an average return of 9%? How much must this investor set aside each year if they only have 25 years to accumulate their desired $1,500,000? What if the investor waits until there are only 15 years to accumulate the $1,500,000?

Rather than saving each year to achieve their $1,500,000, assume the investor in question 2 saves monthly. How much must the investor set aside each month for 35 years? 25 years? 15 years?