Does the surface of a dvd-rom contain microscopic pits?

Drag each label to the correct location on the image list the do’s and don’ts of safeguarding your password. a. keep yourself logged in when you leave your computer. b. don’t write your password down and leave it where others can find it. c. share your password with your friends. d.each time you visit a website, retain the cookies on your computer. e. use a long password with mixed characters.1. do's 2. don'ts

Assume that there is a 4% rate of disk drive failure in a year. a. if all your computer data is stored on a hard disk drive with a copy stored on a second hard disk drive, what is the probability that during a year, you can avoid catastrophe with at least one working drive? b. if copies of all your computer data are stored on three independent hard disk drives, what is the probability that during a year, you can avoid catastrophe with at least one working drive?

You draw two cards from a standard deck of 52 cards, but before you draw the second card, you put the first one back and reshuffle the deck. (a) are the outcomes on the two cards independent? why?