A System Has Two Components That Operate in Parallel, as Shown

Multiple Choice

A system has two components that operate in parallel, as shown in the following diagram. Because the components operate in parallel, at least one of the components must function properly if the system is to function properly. The probability of failure for components 1 and 2, during one period of operation, is 0.2 and 0.03, respectively. Let F1 denote the event that component 1 fails during one period of operation and F2 denote the event that component 2 fails during one period of operation. The component failures are independent. The event corresponding to the above system failing during one period of operation is:

A) F1 and F2.
B) F1 or F2.
C) not F1 or not F2.
D) not F1 and not F2.