Conditional Probability
Example

A system consists of two components.  The probability that the second component functions in a satisfactory manner during its design life is 0.9, the probability that at least one of the two components does so is 0.96, and the probability that both components do so is 0.75.  Given that the first component functions in a satisfactory manner throughout its design life, what is the probability that the second one does also?   [0.926]