A number is chosen at random from the set . Then a number is chosen at random from the set . The probability that given that is
Tap an option to check your answer.
1 markStatisticsProbability and Bayes' theoremTotal probability and Bayes' theoremModerateabout 3 min
DSE 2010 Question 11: Probability and Bayes' theorem
Answer and worked solution
Checking your account…
Plain-text version
A number X₁ is chosen at random from the set {1,2}. Then a number X₂ is chosen at random from the set {1,X₁}. The probability that X₁=2 given that X₂=1 is (A) 1 (B) 1/2 (C) 1/3 (D) 1/4
Also written as: A number X_1 is chosen at random from the set {1,2}. Then a number X_2 is chosen at random from the set {1,X_1}. The probability that X_1=2 given that X_2=1 is
Probability and Bayes' theorem has come up 190 times in 7 exams since 2004.
What this question tests
This question is on Total probability and Bayes' theorem, part of Probability and Bayes' theorem in Statistics.
Reversing a conditional probability and updating beliefs from evidence.
TestStop has 22 past-paper questions on this subtopic.
Similar questions from other papers
- Conditional Probability can be calculated by
- In a year of 366 days, what is the chance that three persons have different birthdays?
- If we twice flip a balanced coin, what is the probability of getting at least one head?
- Two cards are drawn from a full pack of 52 cards at random. The probability of getting a heart and a diamond is (*rounded off to two decimal places*).
- In a population of men in a city, 3% are observed to suffer from cancer, 15% are found to be smokers, while 10% are noticed to be either smokers or cancer patients. If…
Question from the DSE 2010 paper. Solutions are TestStop's own. Not affiliated with or endorsed by any examination authority.