Question 994009
You will have to sit them alternating one student from each class.
The first choice is:
should the student sitting to the left of all other students be a first year student or second year student?
You have {{{2}}} choices.
For each of those choices, you have more choices that are independent of each other.
You have to decide:
in what order to sit the first year students, and
in what order to sit the second year students.
There are {{{5!=5*4*3*2*1=red(120)}}} possible orders to sit the first year students.
There are {{{5!=5*4*3*2*1=green(120)}}} possible orders to sit the first year students.
All in all, there are {{{2*red(120)*green(120)=highlight(28800)}}} ways in which 5 first year student and 5 second year student can be seated on a bench in a examination hall so that no two students of the same class are next to each other.