An algorithm processes an array of size n by operating on its first one-third, its second one-third, its third one-third, and then operating on its third one-third again, recursively. It theån combines the solutions in 21gn time. Derive a recurrence for the running time of above algorithm. You may assume that n=3k for some positive integer k. Use an appropriate method (just pick one method) to solve the recurrence by finding a tight upper and lower bound solution for the recurrence. You must show the procedure of calculation.

1. you have a small business that is divided into 3 departments: accounting, sales, and administration. these departments have the following number of devices (computers, printers, etc.): accounting-31, sales-28, and administration-13. using a class c private network, subnet the network so that each department will have their own subnet. you must show/explain how you arrived at your conclusion and also show the following: all available device addresses for each department, the broadcast address for each department, and the network address for each department. also, determine how many "wasted" (not usable) addresses resulted from your subnetting (enumerate them).