Arectangular prism has a length of 12 in a width of 5 in and a height of 4 and 1/4 in the prism is filled with cubes that have edge length of fourth of an inch how many cubes need to fill the rectangular prism

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?