I'm confused on how to do that?

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?

Pleasse me i need an answer. give me the correct answer. answer if you know it ! the club will base its decision about whether to increase the budget for the indoor rock climbing facility on the analysis of its usage. the decision to increase the budget will depend on whether members are using the indoor facility at least two times a week. use the best measure of center for both data sets to determine whether the club should increase the budget. assume there are four weeks in a month. if you think the data is inconclusive, explain why.

Acommunity group is building a garden on a rectangular lot of land. the lot measures 5x by 10x and the garden will be circular with a radius of 3x. how much of the land will be left over after the garden is built? a. 41 pi x^2 b. x^2 (50 - 9 pi) c. x^2 (50 - 3 pi) d. 41x^2