Help me 39 and 40 pls help me

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?

Anumber is equal to twice a smaller number plus 3. the same number is equal to twuce the sum of the smaller number and 1. how many solutions are possible for this situation

Answer asap! due in 30 minutes! ! 8th grade math