You believe you will spend $$225,000$ a year for $18$ years once you retire in $27$ years. If the interest rate is $6\mathrm{.}40\%$ per year. $($Do not round intermediate calculations. Round your answer to $2$ decimal places.$)$

a$.$ How much must you need saved once you reach retirement. $

b$.$ how much must you save each year until retirement to meet your retirement goal?