Recall that the complement of an event A is the event consisting of all outcomes that are not in A. In application, either event A or its complement, denoted AC must occur. This leads to the equation P(A) P(AC) = 1. Let A be the event an AirTran Airways flight arrives on time and AC be the event an AirTran Airways flight does not arrive on time. Solving this equation for P(AC) gives P(AC) = 1 P(A) Correct: Your answer is correct