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MC II-B Combinatorics problem 9.25 b) solution wrong ?
Question 9.25:
Suppose you are dealt three cards from a standard deck of cards.
Part b):
Find the probability the first two cards are clubs, given that the third card drawn is a club.
In the solution for part b), when you solve the case P(B int A^c)=39/52 · 38/51 · 13/50 + 39/52 · 13/51 · 12/50 + 13/52 · 38/51 · 12/50 = 401/1700.
13/52 · 38/51 · 12/50 corresponds to the case where the first card is a club, the second card isn't a club, and the third card is a club. When you calculate when the second card isn't a club, I think it should be 39/51.
I believe the correct answer to the question is 22/425 (as opposed to 22/423).
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