Noah has d dollars to buy s songs from a website. the the website has an initial charge of $5 to join and then $0.99 for each song. write an equation to represent the amount of money noah will spend on buying songs from the website.

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?