Question 1011662
 
Question:
Five peoole are to be arranged in a row for a photogragh. How many arrangements are there if a married couple in the group insist on sitting next to each other?
 
Solution:
If they stick together, they can be considered as one entity, so the number of arrangements would be P(4,4)=4!.
However, since they could change positions in 2!=2 ways, so the total number of arrangements is 2!4!=48 ways..