Question: 2014 Fall Midterm - 4
Consider 12 boys, 17 girls, and 25 dogs. How many ways are there to arrange them on a line if
- all boys stand next to each other,
- all girls stand next to each other,
- all dogs stand next to each other,
- none of the boys are standing next to any of the girls.
a) $12! + 17! + 25!$
b) $2(12! + 17! + 25!)$
c) $(12!)(17!)(25!)$
d) $2(12!)(17!)(25!)$
Consider 12 boys, 17 girls, and 25 dogs. How many ways are there to arrange them on a line if
- all boys stand next to each other,
- all girls stand next to each other,
- all dogs stand next to each other,
- none of the boys are standing next to any of the girls.
(a)
$2(12! + 17! + 25!)$
(b)
$12! + 17! + 25!$
(c)
$(12!)(17!)(25!)$
(d)
$2(12!)(17!)(25!)$