Ok so that's not a question in a subject but it needs someone who understands in these types of stuff So my wireless keyboard was working fine and yesterday when I put the battery in it, it didn't respond and didn't work, even the wireless mouse didn't work, so I though it was from the battery but when I put the same battery in another wireless mouse it worked and responded quickly, so the thing is in the keyboard, how do it fix it and thanks

Suppose you are an ad-serving company and you maintain a log of cookie data for ads you serve to the web pages for a particular vendor (say amazon). a. how can you use this data to determine which are the best ads? b. how can you use this data to determine which are the best ad formats? c. how could you records of past ads and ad clicks to determine which ads to send to a given ip address? d. how could you use this data to determine how well the technique you used in your answer to part c was working? e. how could you use this data to determine that a given ip address is used by more than one person? f. how does having this data give you a competitive advantage vis-à-vis other ad-serving companies?