Suppose there exactly one packet switch between a sending ho

Suppose there exactly one packet switch 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 R_1 and R_2, 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 L? (Ignore, propagation delay, and processing delay.)

Solution

Delay for first link=L/R1;delay for second link=L/R2

So total delay=(L/R1)+(L/R2)