For our safety, it is important that drivers recognize a stop sign immediately. stop signs are made with exact side and angle measurements to form a regular octagon. they are red so they are easy to see. the three lines drawn below are straight lines. lines a and b are parallel.

Assume that there is a 11% 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 four independent hard disk drives, what is the probability that during a year, you can avoid catastrophe with at least one working drive?