Suppose you are just starting out on your career and want to make a savings plan to assure you put enough away to retire in 30 years. You plan to invest $300 each month in a retirement account. If you expect to earn 10% on average on your retirement investments, how much should you have in your account in 30 years?
Suppose you were to increase the amount you invest each month 10%, up to $330. What is your new retirement account balance in 30 years?
Instead of increasing the amount you invest each month, suppose you chose to work 10% longer, for 33 years. How much would you have in your retirement account after 33 years?
Instead of increasing the amount you invest each month or the length of time you work, suppose you earn 11% returns on your retirement investments rather than 10%. What would be the value of your retirement fund in 30 years?
Returning to the original retirement plan (30 years, $300 per month, 10% per year), suppose you plan to withdraw $3,000 per month from the fund upon retirement. Most people tend to be relatively risk-averse at the time of their retirement. Suppose you move your retirement fund into low-risk investments that you only expect to earn 3% per year. For how many months can you withdraw $3,000 before the funds run out?
Suppose you want to prepare for the possibility that you live a long life after retirement. Assuming the same terms as the previous problem (30 years of saving $300 per month at 10% interest, then upon retirement funds moved into an account that earns 3% per year), how much could you withdraw each month if you needed to make 480 withdraws (40 years of retirement)?