Search any question & find its solution
Question:
Answered & Verified by Expert
If seven persons are to be seated in a row. Then, the probability that two particular persons sit next to each other is
Options:
Solution:
2603 Upvotes
Verified Answer
The correct answer is:
$\frac{2}{7}$
$\frac{2}{7}$
When two particular persons sit next to each other, then we may consider these two person as one group.
So, 6 persons have to be arranged.
Therefore, number of arrangements $=2 ! \times 6$ !
Now, total number of arrangement of 7 persons $=7$ !
Hence, required probability $=\frac{2 ! 6 !}{7 !}=\frac{2}{7}$
So, 6 persons have to be arranged.
Therefore, number of arrangements $=2 ! \times 6$ !
Now, total number of arrangement of 7 persons $=7$ !
Hence, required probability $=\frac{2 ! 6 !}{7 !}=\frac{2}{7}$
Looking for more such questions to practice?
Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.