Exponentiation Is a/an operater?​

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?

Which component acts as a platform on which application software runs

The head restraint should be adjusted so that it reaches a. the top of your ears b. the base of your skull c. the top of the head