Original Question: A computer server is dependent on a component that is critical to its operation. This component, a module A, has a reliability of 80% (=0.8). To increase the reliability of the server, you are considering adding an extra module A as a backup, which has the same reliability of 80% as the module A. The server functions properly if at least one of the two modules (modules A or A') works properly.

Continuation Question:

This is a continuation from the previous question. Suppose that all modules are perfectly positively correlated: if one fails, all other fail at the same time. And if one operates, all other operate at the same time. Re-solve the previous question.

A

The reliability of the system is beyond 100%.

B

The reliability of the system is exactly 100%.

C

The reliability of the system is less than 100% but is close to 100%.

D

The reliability of the system is exactly 80%.

E

The reliability of the system is less than 80%.

F

No correct answers above