what is (10 x 5 ) + 10 =

Free points, i was gonna ask a random question but then i would get banned so i have to ask easy ones dont put random answers tho cuz then people can report them and u may get banned Enjoy the points and dont come at me cuz ik the answer, learned in elementary :)

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?