Q$2$: You've just started your first job at $25$ years old. Your annual salary is $$50,000,$ and you plan to retire at $65.$ You can invest your savings with a return of $5\%$ per year, compounded annually.

Please round your answer to two decimal places, in dollars. $($e$.$g$.12345\mathrm{.}67)$

a$.$ If you save $20\%$ of your salary every year for the first $10$ years $($last deposit on your $35$th birthday$)$ and stop saving afterward, how much will you have by the time you turn $65?$

b$.$ If you don't save anything for the first $10$ years and start saving at $35,$ what percentage of your salary will you need to save every year until retirement to have the same amount as in part a$)?$