$n$ balls numbered from $1$ to $n$ 
If we consider a box containing $n$ balls numbered from $1$ to $n$. If $455$
  is the number of ways to get three balls from the box such that no two
  balls are consecutively numbered, then we have to find the value of $n$.

Someone please help me out in this. I am not getting anything, how to start it?

By the multiplicative rule we get nC1 *n-3C1*n-6C1 (every time we choose a ball its successor and predecessor is eliminated). This is n(n-3)(n-6).
