How many ways can 8 people be seated in a round table if two specific people need to sit together?
Question
How many ways can 8 people be seated in a round table if two specific people need to sit together?
Solution
To solve this problem, we can use the concept of permutations in combinatorics. Here are the steps:
-
Consider the two specific people who need to sit together as one unit. Now, instead of 8 individuals, we have 7 units to arrange (6 individuals + 1 pair).
-
Since it's a round table, the number of arrangements (permutations) for these 7 units is (7-1)! = 6! = 720. This is because in a circular arrangement, we consider one point as a reference and arrange the others in relation to it, hence n-1.
-
However, the two specific people can switch seats with each other, so we have 2! = 2 ways to arrange them.
-
Therefore, the total number of ways to arrange 8 people around a round table with the condition that two specific people need to sit together is 720 * 2 = 1440 ways.
Similar Questions
How many different seating orders are there for eight people sitting in a circle?
The number of ways, in which 5 girls and 7 boys can be seated at a round table so that no two girls sit together is
In how many ways 5 boys sit round the table, so that two particular boys are next to each other?
In how many ways 4 girls and 6 boys can be seated in a row so that no two girls are together?
In how many ways can 8 Indians and, 4 American and 4 Englishman can be seated in a row so that all persons of same nationality sit together?
Upgrade your grade with Knowee
Get personalized homework help. Review tough concepts in more detail, or go deeper into your topic by exploring other relevant questions.