If staff salaries were $44,000/month last year and $53,000/month this year, what is the approximate labor cost Increase in percentage? A: 3%

B: 7%

C: 10%

D: 21%

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?

How are algebraic expressions evaluated using substitution?

Me i’m stuck on all these questions besides the two bottom ones