It costs $15 to attend a golf club with a local pro. Buckets of balls for practice during the club cost $5 each. Select the correct equation in order to find how many buckets can you buy at the club if you have $50 to spend?

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?