Gary King must decide how to invest $$20,500$ that he just inherited. What would be the future value of his investment after $6$ years under each of the following two investment opportunities? $($Round final answers to $0$ decimal places, e$.$g$.5,714.$ Do not round intermediate calculations.$)$

a$.6\mathrm{.}42$ percent compounded quarterly.

Value of investment after $6$ years

$

b$.6\mathrm{.}24$ percent compounded monthly.

Value of investment after $6$ years

$