Suppose there is exactly one packet switch (or router) between a sending host and a receiving host. The transmission rates between the sending host and the switch and between the switch and the receiving host are R1 = 1Mbps and R2 = 2Mbps, respectively. Assuming that the switch uses store-and-forward packet switching, what is the total end-to-end delay to send a packet of length 18000bits? Assume that the propagation speed is 2 * 108 meters/sec, the distance between source and the router is 20,000 km, the distance between the router and the destination is 10,000 km (Ignore queuing delay and processing delay, considering transmission delay and propagation delay).