The figure above shows a pyramid with regular hexagonal base. The length of each side of the
hexagonal face is 4 units and the height of the
pyramid is 7 units. What is the volume of the
pyramid? apothem= 2square roots of 3

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?