3. How long does it take a car to travel: a. 10m at 20m/s
b. 50m at 10m/s
C. 200m at 8m/s
d. 50km at 100km/h

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?