Find the present values of these ordinary annuities. Discounting occurs once a year. Do not round intermediate calculations. Round your answers to the nearest cent.

a$.$ $$800$ per year for $12$ years at $16\%.$

$

b$.$ $$400$ per year for $6$ years at $8\%.$

$

c$.$ $$900$ per year for $6$ years at $0\%.$

$

d$.$ Rework previous parts assuming they are annuities due.

Present value of $$800$ per year for $12$ years at $16\%$ : $

Present value of $$400$ per year for $6$ years at $8\%$ : $

Present value of $$900$ per year for $6$ years at $0\%$ : $