Q8. A teacher decided to play a game in which she wants all the 20 stu

1.	Q8. A teacher decided to play a game in which she wants all the 20 students of thedassroom to sit along a dirde. In how many ways all 20 students is to be seated if2particular students are always to sit together?
Answer» Consider two particular persons as one person. We have 19 persons in all. These 19 persons can be seated around a circular table in (19-1)! = 18! Ways. But two Particular persons can be arranged between themselves in 2! ways. So Total number of arrangements = 18! X 2!

Q8. A teacher decided to play a game in which she wants all the 20 students of thedassroom to sit along a dirde. In how many ways all 20 students is to be seated if2particular students are always to sit together?

Answer»

Consider two particular persons as one person.

We have 19 persons in all. These 19 persons can be seated around a circular table in (19-1)! = 18! Ways.

But two Particular persons can be arranged between themselves in 2! ways.

So Total number of arrangements = 18! X 2!