PLease help ;0 thank you very much

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?

Which equation could represent the relationship shown in the scatter plot? y=−3x−2 y=−3/4x+10 y=−2/3x+1 y=9x−12 scatter plot with x axis labeled variable x and y axis labeled variable y. points go from upper left to lower right.

∠1 and ∠2 are vertical angles. ∠2 has a measure of 63°. what is the measure of ∠1 ? enter your answer in the box.