Consider two hosts, A and B, separated by 100 kilometers and connected by a direct link of bandwidth R-15 Gbps. Assume a packet-switched datagram network is used. A file of 200,000 bits is to be sent from A to B. Suppose that the file is broken up into 30 packets and that the receiver acknowledges each packet. Assume that the sender cannot send a packet until the preceding one is acknowledged, and that the transmission time of an acknowledgment packet is negligible. Assume that the propagation speed over the link is 2.5x10 m/s. How long does it take to send the file