Eight persons stand in a line at random. What is the probability that two persons X and Y don't stand together.
Hints : The sample space in this case is of size 8! Let A be the event that X and Y stand together.
You can consider X and Y tied together as one person so that altogether you have 7! arrangements:
but then in each such arrangement X and Y can interchange their places still staying together:
thus the total number of ways in which X and Y can stand together is 2 x 7!.
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Answer:
eight person stand in a line
Step-by-step explanation:
thus the. tot
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