I am so confused and need answers fast appreciate your help :) (get full points too!)

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?

The following hormone had their receptors in the cell membrane except a-insulin b-tsh c-gh d- cortisol

Which of the following statements would be sufficient to prove that parallelograms pqrs is a rectangle ?