1) Suppose someone earns $70,000 per year for their entire career (no inflation, no raises). They intend to work from age 22 to age 66. Upon retirement, they would like their annual income to be 70% of their old salary. They expect to live until age 86. They estimate they will earn an annual rate of return of 7% on investments. If they start saving at age 22, how much do they need to save per year while they are working to accomplish their goal? What percent of their annual salary does this annual saving represent?

2) Now suppose they go to graduate school, then get a relatively low paying job, then start a family and do not begin saving until age 35. How much must they save per year between ages 35 and 66 in order to have just as much in retirement as if they had started saving at age 22? What percent of their annual salary does this represent?

3) Like above, suppose this person does not have a huge capacity to save for the first 13 years after graduation. But they manage to save $50 per month ($600 per year). How much will this reduce the amount they must save per year between ages 35 and 66 in order to have the same amount in retirement?