Question

$6$ question papers of three different codes A,B,C are to distributed among $6$ students such that no student get the same code of those sitting beside him/her. In how many ways this can be done?

• A. $51$
• B. $60$
• C. $120$
• D. $45$

Answer 1

Answer: (B)

$60$

We have 6 questions paper in three different code

Hence number of ways is $\frac{6!}{3!}$

But we should remove the cases in which the two neighbour students have same paper code It means we should remove identical cases

Hence number of ways are $\frac{6!}{2!3!}=60$