$($Present value$)$ What is the present value of the following future amounts?

a$.$ $$600$ to be received $8$ years from now discounted back to the present at $11$ percent

b$.$ $$300$ to be received $7$ years from now discounted back to the present at $8$ percent

c$.$ $$1,000$ to be received $11$ years from now discounted back to the present at $5$ percent

d$.$ $$1,100$ to be received $5$ years from now discounted back to the present at $20$ percent