Probability Question 408
Four boys and three girls stand in a queue for an interview, probability that they will be in alternate positions is
[UPSEAT 2001]
Options:
A) $ \frac{1}{34} $
B) $ \frac{1}{35} $
C) $ \frac{1}{17} $
D) $ \frac{1}{68} $
Correct Answer: B $ \therefore $ The favourable cases $ =4,!,\times ,3,! $ Hence the required probability $ \frac{4,!,\times 3,!}{7,!}=\frac{24\times 6}{5040}=\frac{1}{35} $ .Show Answer
Answer:
Solution:
Four boys can be arranged in $ 4\,! $ ways and three girls can be arranged in 3! ways.