推 qa77330:跟他拼了 就分有沒有抽到紅球吧 我只會這招 12/01 18:38
推 hchs31705:聯合/邊際? 12/02 00:26
Suppose there are 5 color balls in each of the three urns A1,A2,A3 for which
contains 1,2,3 red balls, respectively. We draw a ball at random from A1 to
A2, and then draw a ball at random from A2 to A3.
a) A ball is then drawn at random from A3, find the probability that the ball
is red.
b) One urn is then chosen at random and one ball is drawn from it also at
random. If the ball is red, what is the probability that the chosen urn
was A3?
請各位幫個忙，謝謝!!
感激不盡!!
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