Question
6 Boys and 5 Girls sat in a row randomly. What is the
probability that no 2 Girls are together?Solution
6 Boys and 5 Girls, i.e., a total of 11 people can be arranged in 11!/6!5! ways or, 462 ways.
For no 2 Girls to sit together, arrangement can be done in the following way: [B are Boys]
_ B _ B _ B _ B _ B _B_
There are 7 spaces that can be taken up by 5 Girls so that no 2 of them sit together.
Number of ways =Â 7 C 5 Â = 21.
Required probability = 21/462 = 1/22
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