NOT A QUESTION!! Alright, if someone answers your question and puts something like this
"Answer is in the link below!" Don't click that sh. it its probably a logger, like why the fu. c.k would you need to download an answer

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?