Consider a scenario where a web server is connected to router R1 by a 400 Mbps link, with 300ms propagation delay. R1 is connected to another router, R2, over a 50 Mbps link with 150 ms propagation delay. A 2 Gbps link connects a LAN with multiple hosts with negligible propagation delay. All packets in the network are 20Kbits.

a. What is the end-to-end delay from when a packet is transmitted by the server to when it is received by a host? Neglect any queuing and nodal processing delays.

b. Assume a cache is added to the LAN and that its hit rate is 40%. What is the average rate of requests being satisfied?