Refer again to problem P$24.$

a$.$ How long does it take to send the file, assuming it is sent continuously?

b$.$ Suppose now the file is broken up into $20$ packets with each packet

containing $40,000$ bits. Suppose that each packet is acknowledged by

the receiver and the transmission time of an acknowledgment packet is

negligible. Finally, assume that the sender cannot send a packet until the

preceding one is acknowledged. How long does it take to send the file?

c$.$ Compare the results from $($a$)$ and $($b$).$