Alisha buys 6 boxes of peanut butter granola bars and 6 boxes of cinnamon granola bars. Let p represent the number of peanut butter granola bars and c represent the number of cinnamon granola bars. Jaira and Emma each write an expression that represents the total number of granola bars Alisha bought. Jaira
6p + 6c

Emma
6(p + c)
Are the expressions equivalent?

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?