Help pls

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?

The cost of turkey is directly proportional to its weight. if a 12-pount turkey costs $27, how much does a 13-pound turkey cost? a. $33.75 b. $36.00 c. $31.00 d. $32.50

Use the linear combination method to solve the system of equations. explain each step of your solution. if steps are not explained, you will not receive credit for that step. 2 + 9 = −26 −3 − 7 = 13