What is the delay of sending a data file from a source station to a destination station? Suppose that the length of the data file is 2 Mbytes and the bandwidth of the channel is 1600 bps, and the network link between the sender and receiver is 20000 Km and the speed of the light inside the link is 2x108 meters/second? Assume that the delay is composed of only transmission time and propagation time.