Mira pours some juice from jug A to an empty jug B. The volume of juice in jug B becomes 5 times of that in jug A. Then Adam pours some juice from jug B into glass C. The volume of juice in glass C is 3 times of that in jug B now. If glass C has 500 ml of juice more than jug B, what is the initial volume of juice in jug A?

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?