Question

There are 4 boys and 3 girls.they sit in arrow randomly.what is the probability that all girls are together?

Answer 1

Thanks for the question!

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The probability that the first slot will be taken by a boy is 4/7
the probability that the second slot will be taken by a girl is 3/6
The probability that the third slot will be taken by a boy is 3/5 layer on top of the surface.


Then 2/4
Then 2/3
Then 1/2
Then 1/1

the probability that all of this will occur is 4/7 * 3/6 * 3/5 * 2/4 * 2/3 * 1/2 * 1/1 which comes out to be (4*3*3*2*2*1*1)/(7*6*5*4*3*2*1) which comes out to be 1/35.

Since this arrangement can only happen in one way, then 1/35 is the answer.


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Hope it helps and solves your query!!