At home Moses uses all his free time to play video games, road and skateboard. He spends 75% of his free te reading. 12.5% of his free time is spent playing video games and he skateboards from 5:15PM to
5:45PM How much free time does Moses get in total?

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?