In an examination hall there are four rows of chairs. Each row has 8 chairs one behind the other. There are two classes sitting for the examination with 16 students in each class. It is desired that i each row, all students belong to the same class and that no two adjacent row are allotted to the same class. In how many ways can these 32 students be seated?

Explanation

`=.^16C_8**!*.^16C_8*8!*8!*8!`

`=(16!)/(8!)^2*8!*(16!)/(8!)^2*(8!)^3`

`=16!*16!*2`.