Dina encoded a secret phrase using matrix multiplication. she multiplied the clear text code for each letter by the matrix (see image) to get a matrix that represents the encoded text. by which matrix does dina multiply the encoded text to get the matrix for the clear text code?

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?