The table below lists the number of layers of centimeter cubes, along with the number of cubes in each layer, in each of four rectangular prisms.
LAYERS OF CUBES IN RECTANGULAR PRISMS
Prism
Number of
Layers
Number of Cubes
in Each Layer
R
3
8
S
5
5
T
6
5
U
7
4
Which rectangular prism has the greatest volume?
A Prism R
B Prism S
C Prism T
D Prism U

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?