There are two fair coins. Coin 1 is tossed 3 times; let be the number of heads. Then Coin 2 is tossed times; let be the number of heads. The probability equals
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2 marks, −0.666666666666667StatisticsProbability and Bayes' theoremTotal probability and Bayes' theoremHardabout 3 min
DSE 2014 Question 44: Probability and Bayes' theorem
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Plain-text version
There are two fair coins. Coin 1 is tossed 3 times; let X be the number of heads. Then Coin 2 is tossed X times; let Y be the number of heads. The probability Pr (X≥2| Y=1) equals (A) 1/2 (B) 4/7 (C) 2/3 (D) 11/18
Also written as: There are two fair coins. Coin 1 is tossed 3 times; let X be the number of heads. Then Coin 2 is tossed X times; let Y be the number of heads. The probability Pr (X>=2| Y=1) equals
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.
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