A game uses a special deck of cards with 40 cards numbered from 1-40. You draw a card from a shuffled deck. What is the probability of drawing a card that is divisible by 2? What is the probability of drawing a card that is divisible by 5? What is the probability of drawing a card that is divisible by 10? Please help with all of these questions! I have no idea

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?