Ten balls are stacked in a triangular array with 1 atop 2 atop 3 atop 4. (think of billiards.) the triangular array is free to rotate. find the generating function for the number of nonequivalent colorings with the colors red and blue. find the generating function if we are also allowed to turn over the array.

The length and width of a rectangle are consecutive even integers the area of the rectangle is 120 squares units what are the length and width of the rectangle

2.5 milligrams is equivalent to how many grams

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?