(a) If the knowledge that an event A has occurred implies that a second event B cannot occur, then the events A and B are said to be 0 A. independent. 0 B. collectively exhaustive. O C. disjoint. O D. the sample space. (b) If event A and event B are as above and event A has probability 0.4 and event B has probability 0.2, then the probability that A or B occurs is 0.0 555