For his birthday party jacob mixed together 8 gal. of brand a fruit punch and 2 gal. of brand b. brand a contains 60% fruit juice an brand b contains 10% fruit juice. what percent of the mixture is fruit juice?

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?