A circular pool is located in the center of a square park. The park, the pool, and some of their dimensions are shown in the diagram below3) What is the radius, in yards, of the pool? ONLY USE NUMBERS IN YOUR ANSWER (no letters) *

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?