Question

person decided to play a game in which he wants all his 20 friends to sit along a circle. In how many ways all 20 friends is to be seated if 2
particular friends are always to sit together?

Answer 1

Start with simpler models. For example, 2 people in a row can be seated in 2 ways, but sitting along a circle, there is just 1 way. 3 people in a row can be seated in 6 ways, but once they are in a circle, there are just 2 ways (draw this to see why). Continue with 4 people and you will soon see the pattern you need for this more complex problem.
For the pair, consider them as one person, with 2 ways to seat them relative to each other.

Answer 2

can u solve it

Answer 3

i got it
thanks

Answer 4

no worries

Answer 5

answers is 2/19

correct or not