What is a fraction between 3/4 and 1

What is (28 + 7 + 6 + 3) x 1/2 show your work

On average a herd of elephants travels 10 miles in 12 hours you can use that information to answer different questions drag each expression to show which is answers

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?