In a network of straight-line tunnels, emergency lights will be installed at select intersections, points where several tunnels meet. The goal is that from every intersection, at least one light should be visible. You can see the light at the intersection where you are standing, and any light at the other end of a tunnel. You are given the network with n intersections, and asked whether installing k lights is enough. Required:
Prove this problem is NP-complete.

Hi plz 11 ! when planning a table, what step comes first: "define the column headers" or "calculate the number of columns/rows"? a. calculate the number of columns/rows b. define the column headers

One of your customers wants you to build a personal server that he can use in his home. one of his concerns is making sure he has at least one backup of their data stored on the server in the event that a disk fails. you have decided to back up his data using raid. since this server is for personal use only, the customer wants to keep costs down. therefore, he would like to keep the number of drives to a minimum. which of the following raid systems would best meet the customer's specifications? a. raid 0 b. raid 1 c. raid 5 d. raid 10

The keyboard usually has six rows of keys. which of the following is not one of the key group categories? letter keys number keys control keys graphic keys