Question #4: Today is Linda's first day of retirement and her 60th birthday. She is not entitled to any pension income and expects no further wages or salary income for the rest of her life. But, she does have an investment account (think RRSP, or TFSA) that currently has a balance of $1,000,000. Luckily for Linda, her bank offers her a generous 3% interest rate per year (APR), with monthly compounding, which is paid on her account balance at the end of every month. So, for example, if she doesn't spend any money from her investment account during that first month of retirement, at the end of the month she will receive $1,000,000 X (0.03)/12 = $2,500 in cash interest and the balance will grow to $1,002,500, etc. Unfortunately, she can't live on $2,500 per month. To cover her retirement (adventures, expenses), she plans to withdraw $6,000 per month, which is (obviously) $3,500 more than the cash interest. She will be eating into her (a.k.a. depleting) principal, which will shrink over time and further reduce the cash interest she earns, all in a vicious cycle. Part A: Compute the age at which she will completely run out of money and exhaust her account, if she continues spending $6,000 per month and continues earning 3% interest. For this question, please ignore income taxes and inflation (both of which we will discuss in greater detail, later on in the semester. You should be able to solve this with a simple formula/equation and should not have to resort to (blindly & mindlessly) building a spreadsheet that does this recursively Part B: Generalize the above and assume Linda is x-years-old, has M dollars in her investment account, earns an interest rate of r per year, and spends or consumes c per year (that is c/12 per month) indefinitely. Write down a formula for the age at which Linda runs out of money