Probability Question 69
Question: A box contains 10 mangoes out of which 4 are rotten. 2 mangoes are taken out together. If one of them is found to be good, the probability that the other is also good is
[EAMCET 1992]
Options:
A) $ \frac{1}{3} $
B) $ \frac{8}{15} $
C) $ \frac{5}{18} $
D) $ \frac{2}{3} $
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Answer:
Correct Answer: C
Solution:
Number of ways of selecting two good mangoes = $ ^{6}C_2=15 $ .
Number of ways that at least one of the two selected mangoes is to be good $ ={}^{6}C_1\times {}^{9}C_1=54 $
$ \therefore $ Required probability $ =\frac{15}{64}=\frac{5}{18} $ .