Abag of 13 marbles contains 2 greeb, 7 blue, 1 yellow, and 3 red marbles. if a blue marble is oulled at random and not put back, give the probability that the second marble will be yellow

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?