from computer networks a system approach book

please answer the following ..

Calculate the latency (from first bit sent to last bit received) for the following:

(a) 10-Mbps Ethernet with a single store-and-forward switch in the path, and a packet size of 5000 bits. Assume that each link introduces a propagation delay of 10s 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 cut-through switching: It is able to begin retransmitting the packet after the first 200 bits have been received.

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