please help me. this is on ixl and if i get one question wrong then i have to restart and im already on 20 and i need at least 60,70,or 80 to pass and this is a missing assignment. If its correct ill mark branliest.

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?