Free Practice Question
PS · Problem Solving
655-705
Probability
Events A and B are independent. The probability that both events A and B occur is 0.15. Additionally, the probability that event A occurs while event B does not occur is 0.45. What is the probability that at least one of the events A and B occurs?
Answer Choices
Correct answer marked belowA
0.55
0.7
Correct
C
0.75
D
0.8
E
0.85
See the full step-by-step explanation
You can see the correct answer above. Sign in for free to unlock the complete worked solution.
Track your performance and improve
Get detailed analytics, unlock full explanations, and move up difficulty tiers as you practice.
Explanation
Preview
Official Explanation
Official
To find the probability that at least one of the events A and B occurs, we can use the formula: Probability that Event A occurs and B does not occur + Probability that Event B occurs and A does not occur + Probability that both events A and B occur. This can be expressed as: A*(1-B) + B*(1-A) + A*B. Given that the probability that both events A and B occur is 0.15 (i.e., A*B = 0.15) and the probability that event A occurs while event B does not occur is 0.45 (i.e., A*(1-B) = 0.45), we can solve for A and B. From A*(1-B) = 0.45, we have A - AB = 0.45. Substituting AB = 0.15 into this…
Read the full explanation
Sign in for free to see the complete step-by-step solution to this question.
Comments
Sign in to join the discussion
No comments yet
Be the first to share your thoughts and help others understand it better.
Sign in to commentWhat this question tests
What it tests
Your ability to compute probabilities of single and compound events, including 'at least one' questions.
Common trap
Forgetting to use the complement for 'at least one', or treating dependent events as independent.
Details
Difficulty
655-705
Type
PS
Category