Through what activity can you achieve the goal of a peaceful retirement and reaching your milestones in life?

According to this excerpt, a key part of our national security strategy is

Ichelle is attending college and has a part-time job. once she finishes college, michelle would like to relocate to a metropolitan area. she wants to build her savings so that she will have a "nest egg" to start her off. michelle works out her budget and decides she can afford to set aside $9090 per month for savings. her bank will pay her 4 %4% per year, compounded monthly, on her savings account. what will be michelle's balance in five years?

You are the manager of a large crude-oil refinery. as part of the refining process, a certain heat exchanger (operated at high temperatures and with abrasive material flowing through it) must be replaced every year. the replacement and downtime cost in the first year is $165 comma 000. this cost is expected to increase due to inflation at a rate of 7% per year for six years (i.e. until the eoy 7), at which time this particular heat exchanger will no longer be needed. if the company's cost of capital is 15% per year, how much could you afford to spend for a higher quality heat exchanger so that these annual replacement and downtime costs could be eliminated?