Miguel is reading the book call of the wild by jack London during the first 3 days of the week he read and average of 15. Pages per day during the next 2 days Miguel averaged 25 pages per day for all five days what was the average number of pages Miguel read?

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?