What is the final answer? SHOW YOUR WORK.

24/3*2^2/2*3+(20-10)-40

Assume that there is a 4% 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 three independent hard disk drives, what is the probability that during a year, you can avoid catastrophe with at least one working drive?

Im doing this last minute and literally none of my neighbors or people that my dad works with use excel so if anyone could me make up an example

List a few alternative options and input and output over the standerd keyboard and monitor. explain their functioning in details.