Please assist with how to figure these out with excel??

Youve decided you want to get your MBA, which will cost you $15,000. If you have $10,000 now and can make 7.5% on your money, how soon can you attend classes?

Youve just been hired on your first job! Congratulations. The company has a 401(k) plan and youve decided to put 10% of your $45,000 salary away each year. If you can earn 8% annually on your money, how much will you have 35 years from now when youre ready to retire?

Youre aunt Edna just retired at the age of 65 years old. She has an annuity with $750,000 and wants to begin taking payments until shes 90 years old. If the annuity can earn 4.5% annually, how much can she take each year before the account gets to $0?

You have to choose between investing your $1000 in a band CD that pays 2.5% annually, or into a 20 year treasury bond that pays 2.2% semi-annually. Which investment pays a better rate of return?