Dave rented a limousine for his wife’s birthday. The hourly rate is $60. They used the limousine for 5 hours, plus Dave gave the driver a 10% tip. How much did he spend in total for the hourly charges plus tip?

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?