Please show steps.

3. Consider two hosts A and B separated by 2 nodes (switches or routers), A wants to send a file of size M 15 Mbytes over to B. Each link has the same data rate C = 1.5 Mb/s. a. Assume message switching, how long would it take for the whole file to be received by B? Explain your assumptions. Comment. Write first the formula giving the time in terms of C, M, and possibly other parameters. b. Assume packet switching and that all packets have the same size L=1200 bits, how long would it take for the whole file to be received by B? Explain your assumptions. Write first the formula giving the time in terms of C, M, and possibly other parameters. Comment and compare