When the "swen" virus infected someone's system, it made significant changes to the registry that caused it to be extremely difficult to be removed by hand. what were those changes and why did those changes make it so difficult to remove?

You will subnet the network address 172.31.103.0/24. the network has the following requirements: · room-114 lan will require 27 host ip addresses · room-279 lan will require 25 host ip addresses · room-312 lan will require 14 host ip addresses · room-407 lan will require 8 host ip addresses how many subnets are needed in the network topology?