Homework Help

8 chairs are placed at the sides of a long table in such a way that three are 4 chairs...

user profile pic

wonghoongkok | Student, Grade 9 | eNoter

Posted June 10, 2013 at 12:38 PM via web

dislike 1 like

8 chairs are placed at the sides of a long table in such a way that three are 4 chairs on the left and 4 chairs on the right. 8 children are to be seated on these chairs. If 2 specific children want to sit on the same side, calculate the number of ways all the 8 children can be seated. 

1 Answer | Add Yours

Top Answer

user profile pic

llltkl | College Teacher | Valedictorian

Posted June 10, 2013 at 2:04 PM (Answer #1)

dislike 1 like

Let the two sides of the long table be A and B.

Two children who wish to sit on the same side (say, side A) can be accommodated in two chairs in either of the sides in `2*^4P_2` ways. Now six children are left who can sit on six chairs on both the sides of the table in 6! ways.

Hence, the total number of ways in which 8 children can be seated

= `2*^4P_2 * 6!`

= `(2*4!*6!)/((4-2)!)`

= 17280

=>answer.

 

Sources:

Join to answer this question

Join a community of thousands of dedicated teachers and students.

Join eNotes