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Suppose that 10 good and three dead batteries are mixed
Chapter , Problem 18(choose chapter or problem)
Suppose that 10 good and three dead batteries are mixed up. Jack tests them one by one, at random and without replacement. But before testing the fifth battery he realizes that he does not remember whether the first one tested is good or is dead. All he remembers is that the last three that were tested were all good. What is the probability that the first one is also good?
Questions & Answers
QUESTION:
Suppose that 10 good and three dead batteries are mixed up. Jack tests them one by one, at random and without replacement. But before testing the fifth battery he realizes that he does not remember whether the first one tested is good or is dead. All he remembers is that the last three that were tested were all good. What is the probability that the first one is also good?
ANSWER:Step 1 of 2
Given that,
Number of good batteries = 10
Number of dead batteries = 3
The good ones and the dead ones are mixed up. Jack tests them one by one, at random and without replacement. But before testing the fifth battery he realizes that he does not remember whether the first one tested is good or is dead. He remembers that the last three that were tested were all good.
It is required to compute the probability that the first one is also good.