A tribe of eight Native Americans sits in a circle around a campfire. If the chief must sit between his mother and his wife, how many different seating arrangements are possible? Two seating arrangements are considered the same if each individual has the same person to the right and the same person to the left in both.
Here's my take :
Fix the chief in any position
We have two ways to arrange the mother and wife......either the wife is on the left of the chief and the mother on the right, or vice-versa
And the other 5 members of the tribe can be arranged in 5! ways
So...the total possible arrangements are 2 * 5! = 2 * 120 = 240