I’m stuck on this anyone?

On average, how many more hits will he get when he bats 100 times at home during the day as opposed to 100 times away at night?

The tile along the edge of a triangular community pool needs to be replaced? ?

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?