2. a)how many possible ways that the two of the
brothers are not sitting together?
5 boys and 5 girls
(111)! 2! 2!(101)! = 6 531 840
# of ways the
# of ways the
# of ways
# of ways
they can be 2 brothers
two brothers
the couple
seated in a can sit next to
can be
can be
round table each others.
rearranged rearranged
and the
couple
insist on
sitting
together.
2
3. b)how many possible ways can you sit
the children or alternate seats?
H W
B G 5!5!2! = 28 800
B
G # of ways the
# of ways the # of ways the
boys can be
girls can be
G couple can be
rearranged
rearranged
B rearranged
B
G G
B
3