A hint to get started
Use a manager as the circular reference
An office has 8 staff consisting of 5 employees,1 translator,1 secretary and 1 manager.
(i) The group stands in a line.
(a) Find the number of different possible arrangements. mark
(b) Find the number of different possible arrangements if the secretary and the manager do not stand together. marks
(ii) The group sits in a circle where the seats are indistinguishable.
(a) Find the number of different possible arrangements. mark
(b) Find the number of different possible arrangements if the secretary sits beside the manager, and the translator sits opposite the manager. marks
[2011/JJC/II/5]
CJC · Review problems · Question 9
Fix the manager’s position before placing the opposite translator.