Statistics And Probability Question 284

Question: Ten students are seated at random in a row. The probability that two particular students are not seated side by side is

Options:

A) $ \frac{4}{5} $

B) $ \frac{3}{5} $

C) $ \frac{2}{5} $

D) $ \frac{1}{5} $

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Answer:

Correct Answer: A

Solution:

  •                 Total ways  $ =10! $                     Two boys can sit side by side in  $ 2\times 9! $  ways.                    So probaibility  $ =\frac{2\times 9!}{10!}=\frac{1}{5} $             Thus the probability that they are not seated together is  $ 1-\frac{1}{5}=\frac{4}{5}. $