Jacob owes his friend Omar some money that he borrowed. On Tuesday, he gave Omar $5.24. Now, Jacob only owes $12.88. Part A: Write an equation that could be used to determine the amount of money, x, that Jacob borrowed from Omar.
Part B: Solve for x, the amount of money that Jacob borrowed from Omar.

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?