Probability Question 96
Question: Four boys and three girls stand in a queue for an interview, probability that they will in alternate position is
[UPSEAT 2001]
Options:
A) $ \frac{1}{34} $
B) $ \frac{1}{35} $
C) $ \frac{1}{17} $
D) $ \frac{1}{68} $
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Answer:
Correct Answer: B
Solution:
Four boys can be arranged in $ 4! $ ways and three girls can be arranged in 3! ways.
$ \therefore $ The favourable cases $ =4!\times 3! $ Hence the required probability $ \frac{=4!\times 3!}{7!}=\frac{6}{7\times 6\times 5}=\frac{1}{35} $ .
BETA
