8. Calculate the latency (from first bit sent to last bit received) for the following: (a) 100 -Mbps Ethernet with a single store-and-forward switch in the path and a packet size of 12,000 bits. Assume that each link introduces a propagation delay of 10 s and that the switch begins retransmitting immediately after it has finished receiving the packet. (b) Same as (a) but with three switches. (c) Same as (a), but assume the switch implements "cutthrough" switching; it is able to begin retransmitting the packet after the first 200 bits have been received. 9. For each of the following operations on a remote file server, discuss whether they are more likely to be delay sensitive or bandwidth sensitive: (a) Open a file. (b) Read the contents of a file. (c) List the contents of a directory. (d) Display the attributes of a file