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Ten people are sitting around a round table. Three of them are chosen at random to give a presentation. What is the probability that the three chosen people were sitting in consecutive seats?

 Jun 27, 2018
 #1
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We  have  C (10,3)  =  120  possible total selections of any three people

 

And  there  10  possibilities of selecting  3 people who sit together

( The first group occupies  seats 1, 2 and 3  and the last group occupies seats 10, 1 and 2)

So

1 2 3

2 3 4

3 4 5

.

.

.

10 1 2

 

So....the probability is just    10 / 120    =  1 /12

 

 

cool cool cool

 Jun 27, 2018

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