The probability of the occurrence of event A in an experiment is 1/3. If the experiment is performed two times and event A did not occur, then on the third trial event A _____.
A) must occur
B) may occur
C) could not occur
D) has a 2/3 probability of occurring

Question

Quizplus · Accepted Answer

The occurrence of event A on each trial is independent and does not affect the probability of occurrence on subsequent trials. Therefore, even if event A did not occur in the first two trials, there is still a 1/3 probability of it occurring on the third trial. Choice A is incorrect because there is no guarantee that event A must occur. Choice C is incorrect because event A has already occurred in the experiment with a 1/3 probability. Choice D is incorrect because the probability of event A occurring on the third trial remains 1/3, as each trial is independent.

The Probability of the Occurrence of Event a in an Experiment