1. The reliability of a hard-disk drive is typically described in terms of a quantity' called mean time between failures (MTBF). Although this quantity' is called a "time, " the MTBF actually is measured in drive-hours per failure

If a system contains 1000 drives, each of which has a 750, 000-hour MTBF, which of the following best describes how often a drive failure will occur in that disk farm: once per thousand years, once per century, once per decade, once per year, once per month, once per week, once per day, once per hour, once per minute, or once per second? Support your answer.

2. Using the Hamming Single Error Correcting, Double Error Detecting Code for the following questions.

a. Encode the number 0x72.

b. Consider the encoded number 0x375 (8 bits plus 4 parity bits). Is there an error? If so, where is the error?

c. Consider the encoded number 0xC55 (8 bits plus 4 parity bits). Is there an error? If so, where is the error?