A hint to get started
Count adjacency in the row and circle as disjoint cases
There are 9 people including John, Mary and Gary. They are to arrange themselves into a row of 4 people and a circle of 5 people. Find the number of ways they can arrange themselves if
(i) there are no restrictions. marks
(ii) John and Mary are beside each other. marks
(iii) John, Mary and Gary are part of the group that forms a circle, and John and Mary are separated from each other. marks
[2011/CJC/II/6(a)]
CJC · Review problems · Question 6
In(ii), the adjacent pair must belong together to either the row or the circle.