Two vehicles head toward each other from opposite ends of a freeway 1524 kilometers long. If the speed of the first vehicle is 65 kilometers per hour and the speed of the second vehicle is 62 kilometers per hour, how long will it take before the vehicles pass each other?

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?