How to save customised keyboard shortcuts on word

If an improvement creates no significant change in a product’s performance, then it is a(n) ? a0 design improvement. (there are no answer choices)

Assume that there is a 4% 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 three independent hard disk drives, what is the probability that during a year, you can avoid catastrophe with at least one working drive?

My has been slow anyone else’s ?