In how many ways can Ann, Bob, Chuck, Don and Ed be seated in a row such that Ann and chuck are not seated next to each other?
Select
A) 72  B) 48  C) 56  D) 76  E) 96
When the constraint on an arrangement says,Two people should not be seated together,we do just the opposite. We make them sit together! Kind of tie them with a thread and assume they are one unit!   Let's see why....   These 5 people can be arranged in 5! ways. These are the total number of ways you get.   Now, when we tie 2 people together, we have only 4 entities to arrange. We can do this in 4! ways. But in each of these entities, the two people can sit in two different ways (AB and BA). So number of ways in which these two people sit together is 4!*2!.   Now, the ways in which these two people will not be together will be 5!- 4!*2! = 4!(5 - 2) = 72   72nswer :72
<result>A</result>
In how many ways can Ann, Bob, Chuck, Don and Ed be seated in a row such that Ann and chuck are not seated next to each other?