PLEASE help with a$,$b$,$cYou want to be a millionaire when you retire in $40$ years.

a$.$ How much do you have to save each month if you can earn an APR of $12$ percent? $($Do

not round intermediate calculations and round your answer to $2$ decimal places,

e$.$g$.,32\mathrm{.}16.)$

b$.$ How much do you have to save each month if you wait $10$ years before you begin

your deposits? $($Do not round intermediate calculations and round your answer to $2$

decimal places, e$.$g$.,32\mathrm{.}16.)$

c$.$ How much do you have to save each month if you wait $20$ years before you begin

your deposits? $($Do not round intermediate calculations and round your answer to $2$

decimal places, e$.$g$.,32\mathrm{.}16.)$